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Blockchain in Stock Market Transformation: A Systematic Literature Review

Blockchain, which is the core technology for Bit coin and other digital currencies, is a disruptive technology, especially in the Stock Exchange Market. Although blockchain has much potential in transforming the traditional stock exchange market, blockchain research in this field is still in its infancy. Business scholars began publishing studies related to blockchain in the Stock market transformation in 2015. In this research, we did a PRISMA guided systematic literature review of blockchain in the Stock market transformation from 2015 to 2019. The results show that even though there is an increase in studies, more empirical research is required to utilize the potential of blockchain technology fully. The findings also provide important insights into the current state of a blockchain scholarly study, including its top advantages and legal obstacles, the risk associated with implementing this technology, and the identification of various promising blockchain models currently being proposed in the stock market. We find that blockchain transforms the stock market remains in an early-stage research domain in terms of theoretical basis, methodological diversity, and empirically grounded work. Hence, this research identifies the research gaps and highlights areas where we need a further study that researchers can utilize. Key-words: Blockchain, Stock Market, Distributed Ledger, Securities Exchange, Systematic Review.


Introduction
Blockchain is defined as an immutable public ledger or distributed record database of all digital events and transactions that have been executed and shared by all the participating entities.
During the 2009 financial crisis, Satoshi Nakamoto introduced the Blockchain concept in his paper titled "Bit coin: A Peer-To-Peer Electronic Cash System" [1]. Through this, he describes an electronic Eliminating some of the intermediaries from the securities exchange process speeds up the settlement process and enables greater precision in trade. Trading transactions in blockchain thus decreases information redundancy and thus improves accuracy [7].

Securities Exchange Market: Current Scenario
A securities exchange or stock exchange market can be described as a marketplace where traders and stockbrokers can purchase and sell securities such as asset and bond shares and other financial tools. In a centralized program that governs all trading activities, the conventional financial markets are implemented [8]. An order is an instruction to buy or sell an asset at a given market price; and most of the times, the broker intermediates an order. In stock markets, it is possible to execute mainly three different types of orders, as shown in Figure 1. The traditional capital market system depends on centralized components. Stock Exchange, Settlement System, Clearing House, and Centralized Repository are various entities that make up the existing securities market. This system has many disadvantages. One of the key disadvantages of the traditional system is that a single third party control and governs the network, which makes the system more vulnerable to attacks and failures on a single level. Also, one central third party has handled every transaction in the system, which has created an oppressive structure. The owner controls the payments [9], which does not benefit from the low fees that a decentralized system can offer. Also, in the present scheme, the approval of new business activity only takes place through the intermediates, who are the brokers in the commercial market. Brokers are the trusted registered entities acting in exchange for a fee on behalf of the clients' trade market. Another big downside of managing each transaction is the high processing and settlement time. Depending on the form of exchange, a trade in the conventional system would take T+2 or T+3 days [10]. Only a fully

Prior Research
Ever since the introduction of blockchain in 2008, much research is being carried out in this area. Smart contracts and Ethereum concepts gave a new dimension to blockchain technology. They introduced the concept that blockchain can be extended to many different business areas. There are many research papers, which explain how decentralization can be achieved using the distributed Ledger Technology [11].
Systematic Literature Reviews concerning the development of the Stock Exchange Market using Blockchain technology appear to be very minimal to the best of our knowledge. The first paper regarding decentralization and Stock Market appeared in 2015. Later in 2016, Lee explained a blockchain model of the Stock Market, which can overcome the limitations of the traditional Structure of the Securities Exchange market [12]. Since then, many theoretical frameworks were suggested by researchers using blockchain. Only in 2018, we see empirical research providing statistical data regarding the efficiency of blockchain technology in the Stock Market. Here, the Stock Market was developed using Ethereum, and using statistical data proved that blockchain markets gave better results than the traditional markets by providing more transparency in trading, low transaction fees, etc. [13].
The previous studies describe different models implemented using blockchain technology and their advantage. However, they do not examine the feasibility of these models. The area of research related to blockchain has a fairly short history and is evolving rapidly. Therefore, to direct new research activities, a fresh overview of the more recent research work needs to be given, especially in the blockchain domain in the security exchange market [14].

Methodology
This study aims to review current studies and their results and summarize research efforts in stock market blockchain implementation and how it can be used to address the existing stock market structure limitation [15].We introduced the following four research questions to make the study more focused: The traditional securities exchange market has several disadvantages. The unique characteristics of blockchain can tackle all the problems currently faced in the securities exchange market. Here, we discuss those unique properties and how they can be used to overcome the problems.

Q2: What are the latest blockchain developments in Stock Market?
Blockchain has diversified away from sole crypto currency. Many countries are currently researching how to use blockchain properties to overcome the limitations of the existing stock market structure [16]. An analysis of the recent developments happening in the stock market concerning blockchain, the countries currently focusing on blockchain developments, and have implemented some of the blockchain features in their existing structure will be discussed.

Q3: What are the different blockchain models proposed to overcome the existing limitations of the stock market?
Researchers have suggested different blockchain models, which can overcome the existing limitations of the stock market. A detailed review of the existing blockchain models proposed in the stock market and to analyze the feasibility of this model will be addressed [17].

Securities Exchange Market?
Implementing blockchain in Securities involves many legal challenges. An analysis of the legal issues and laws required while implementing blockchain in the Securities Exchange Market.

Methods
Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations have been adopted to standardize the characteristics of this systematic literature review [18].

Selection Criteria and Literature Search Strategy
The literature was searched through Scopus by Document search from 2015 to 2019 with the keywords of "Blockchain" AND "Stock Market," "Blockchain" AND "Securities Exchange," "Distributed Ledger" AND "Securities Exchange" and "Distributed Ledger" AND "Stock Market." Another database used is Google Scholar (GS), using the keywords "Blockchain, Stock Market, Securities Exchange Market, and Distributed Ledger" as search terms. Within Google Scholar, we screened the first 150 search records [19]. Furthermore, we checked all potentially applicable papers and book chapters on the reference lists. We chose Google scholar and Scopus because Google Scholar provided international and interdisciplinary research papers. At the same time, Scopus has more peer-reviewed papers. We took out redundant documents. Based on the following questions, the abstracts of the selected papers were scrutinized. We shortlisted those articles for further studies whose answers to all questions were yes [20].
• Is the article about Blockchain implementation in Stock Market?
• Is the focus of the paper on the Blockchain and Securities Exchange Market?
• Does this article address any of the problems in the existing Securities Exchange Market?
• Is it a conference article/journal/book chapter?
• Is the paper written in English?
After screening the abstract, the shortlisted papers were extensively read to ensure that earlier versions of the same article were excluded. The article's main emphasis was on the data-driven approach.

Study Selection
A simple Google Scholar article search yielded 16,300 references. 150 Google Scholar records were selected and evaluated. Scopus search yielded 80 papers. These 230 references were checked for duplicates [21]. From these papers, 27 papers were found relevant to the selected topic of research. Before 2015, we do not see any research papers on this topic. That is why we selected the timeline from 2015 to 2019. The flow chart of the study selection process is shown in Figure 2.

Results
This section highlights the initial analysis of our selected literature review population. The papers are grouped according to the geographic distribution, publication year, and type of papers, and research methods [22].

Geographic Distribution and Publication Year
The first analysis is based on the year in which the selected research population is published.  The geographic distribution by continents is also analyzed (See Figure 4). The regions where the selected literature belongs are Europe (41%), Asia (37%), followed by North America (15%), and Australia (7%). One of the main reasons for the increase of blockchain research in Europe is the research done by many start-up companies and how blockchain helps address data security problems

Classification of the Selected Literature
The first classification of the selected literature population is based on the research methods adopted, which helps define the current state of research on the subject and what research is needed to go further in this field. In our literature population, the research methods identified are exploratory studies (63%), followed by theoretical frameworks (33%), systematic reviews (11%), statistics (7%), case studies, and comparative studies (both 4%). The above figures indicate that blockchain implementation in the Securities Exchange market needs further scientific analysis, case studies, and comparative studies. To identify the current state of research of blockchain in the Stock exchange market, we did a high-level analysis of the selected literature population based on the relative proportion of empirical and conceptual papers ( Figure 6). Empirical papers focus on measurable and observable methods to explain our classification method, using various quantitative and qualitative activities. In contrast, conceptual papers address blockchain concepts, hypotheses, benefits, implementations, and challenges without gathering primary data or analyzing secondary data. 89% (n=24) of our total selected literature population of 27 papers were conceptual, and 15% (n=3) were empirical. The first empirical study was published in 2018. It received statistical data, providing promising results for the stock exchange market from implementing the Ethereum blockchain. Figure 7 presents a conceptual vs. empirical paper ratio over a chosen period (2015 to 2019). The figure indicates very little improvement in the ratio of conceptual papers and empirical papers published each year, which shows that blockchain is a new concept in the securities market, and the work in this area is also growing. Figure 8, however, indicates that the rate of academic transformation from the conceptual study to empirical research remains in the initial stages of a new topic.  The study analyses the suitability of applying blockchain in different fields. The suitability is analyzed using an evaluation framework that contains a list of criteria along with a process.
The study shows that identity management and supply chain will benefit from using blockchain. In contrast, the design and weakness of blockchain render the stock market and Electronic Health Records unsuitable yet.
Larissa Lee (Business et al.

2016)
The study discusses a peer-to-peer security exchange scheme, the legal implications, and how such a system would suit existing legislation and regulation.

Discussion
The second stage of our research is outlined in this section. The main aim is to discuss the answers to each research question that we have found. Following this, we discuss this research limitation, its relevance, and the implications for future studies [28].

Exchange Market?
Blockchain provides a decentralized solution that tackles all the problems of the traditional Securities Exchange market. The unique properties of the blockchain like self-enforced validation, transparency, low transaction fees, global agreement of all the transactions that take place help to create a Securities exchange market that can overcome all the limitations of the traditional system.
Self-enforced validation is accomplished using a smart contract, which is a piece of code reflecting various business laws. Like the transactions, the blockchain also records the smart contracts and gets activated during the transaction calls [29]. Smart contracts decide which node will change its status according to the results obtained after its execution. They also represent agents with functionality and state that could be activated even after the successful execution at any time [30]. Consequently, the main objective of smart contracts is to remove any third-party agents and operate in compliance with the pre-established rules that offer a fair-trade climate. Smart contracts also depend on the blockchain framework implementing them. Even though Ethereum is the most developed platform for smart contracts, many other platforms like Side chains, NXT, and Hyper ledger implement smart contracts [31]. In addition to this, Blockchain technology will offer lower costs than existing legacy systems. It will require less maintenance while eventually reducing transaction costs in the long run. Blockchain would incorporate automation into the necessary post-trade activities. Instead of days, securities can be solved in minutes, i.e., real-time settlement with a greater degree of transparency and accountability along with supply chain management and liquidity [32].

Q2: What are the latest blockchain developments in Stock Market?
Blockchain is a promising breakthrough technology, but it is still in the early stage of development in the Securities Exchange Market. Once it is implemented, the present-day intermediaries in the market (e.g., brokers) will have a major role in change and responsibilities.
Here, we summarize some of the recent blockchain developments in the Securities Exchange Market:

i. National Association of Securities Dealers Automated Quotations Exchange (NASDAQ), which is the second-largest Stock Exchange in the world, launched the Private Equity
Exchange on top of blockchain in 2014 called 'Linq' in collaboration with chain.com, the leading provider of blockchain infrastructure to financial institutions and businesses, which helped to promote safe issuance and transfer of private-held companies' shares in the study of the blockchain platform [33]. It was also intended to provide key functionalities, such as the Cap table and investor relationships for pre-IPO or private companies. Due to the involvement of multiple third parties, the current stock trading process in this exchange is slow and inefficient. Compared to the conventional method, this product is incredibly simple, traceable, and effective.
ii. Overstock, an e-commerce corporation, launched the 'tZERO Crypto.' This blockchain platform issues its corporate bonds, which helped eliminate naked short selling and reduce the settlement time to almost zero. Overstock earned regulatory approval to issue equities through its blockchain, six months after the bond's issue. The company also announced in September 2016 about working with regulators on more improvements for its network is collaborating with Keystone Capital.
iii. Medici is the blockchain subsidiary of Overstock.com, which offers shares that use Bit coin 2.0 counterparty implementations. The goal behind Medici was to establish a stock exchange. Counterparty is a protocol applying conventional financial instruments as smart contracts executing themselves. These smart contracts enable, validate and execute contract negotiation and remove the need to provide a physical document. It also removes the need for a broker or a bank.
iv. Another landmark in the Securities Exchange Market will be the Australian Stock Exchange (ASX) launch, using Blockchain technology. In January 2016, ASX purchased a 10-million stake in New York-based Digital Asset Holding to fund R&D in blockchain applications. ASX revealed after a few months that it was completing the first iteration of a new distributed ledger to replace its current settlement system, known as CHESS. The procedure included collaborating during the implementation period with regulatory bodies in Australia and related stakeholders in the trade. ASX completed the development and is currently in the testing phase. This product is considered to be a breakthrough for the distributed ledger technology in Stock Market.

v. Block stream is a blockchain development company. Its open-source project called 'Elements'
focuses mainly on side chains to prevent fragmentation, security, and other crypto currenciesrelated problems. Elements allow you to issue multiple different asset types on a single blockchain, opening up several new usage instances for implementation. The application can include securities registration, bonds, stocks, and derivatives to bank balances and mortgages. This section outlines the best-identified blockchain models proposed for the Security Exchange market from our systematic review population. Table 3 shows the 6 best blockchain models in the Stock market. The majority of the blockchain models are proposed with the Ethereum platform.
The blockchain model using machine learning can be viewed as the best identified one. It gives a new perspective of combining two technologies and the added advantage of prediction using Machine learning. Table 3 -Review of best identified blockchain models in stock market

Author Description
Larissa Lee (Business et al.

2016)
The blockchain model is proposed using Ripple and Ethereum platforms. This model utilizes the underlying blockchain principles with the SHA-256 algorithm and smart contracts. Ethereum has increased transaction speed, and confirmations from Ripple take only a few seconds to complete. As a public ledger, a copy of all transactions will be available in each node, eliminating some of the shrouds of confidentiality covering most of today's dark pool trading and high-frequency, and enabling traders to trade directly through an exchange that eliminates many layers of intermediaries like brokers.
Mahdi H. Miraz and David C. Donald (Miraz and Ali 2018) This model uses Proof of Stack (PoS) for matching and randomizing round-robin clearing and settlement approaches. A central mechanism of trade will carry out the matching of any purchase and sale order of transaction. It will be performed jointly by brokers and dealers. However, the central counterparty clearing house (CCP) will also have power over clearance and settlement. This system provides advantages such as a better trustworthy and stable market, lower transaction costs, and openness than the traditional approach used in the stock exchange market. It can also replace the exchange operators with the BC system building engineers as intermediaries.

Vijaya Kittu Manda, Dr. S.S. Prasada Rao (Manda 2019)
A hybrid blockchain model is proposed for the mutual fund system. The permission private segment provides information (such as investor transaction information) only to and by authorized parties. In contrast, the public segment provides information (such as day-end NAV data, factsheets, etc.) to all users without any restrictions. Smart contracts are used for the information (and fund) flow between the stakeholders as and when necessary. The user interface and interaction with the blockchain network will be through a DAPP (Decentralized Application). Andreea Vesa, Antal Marcel, Claudia Pop, Cristian Pop, Teodor Petrican, Tudor Cioara, Ionut Anghel, Ioan Salomie .(Pop et al. 2018) A decentralized Exchange Platform was developed using the smart contract, which served as an improved ledger for orders. Various Smart Contract states were specified with the required details. The smart contract also defined the order action as a structure that contains details about the address of the person, the timestamp of the action when it was registered in the network, the number of assets transacted, and the price for the sale or purchase. The mapping between the owner's address and the sum of securities held was done by the decentralized depository that kept track of all the assets and replicated the data in the network. The model implemented in Ethereum showed positive results offering lower prices for partially filled order books and full order books. Katya Malinova, Andreas Park (Malinova and Park 2016) This model highlights the three critical features of the distributed ledger, allowing for new market designs relative to the current security trading environment. The first is the electronic design of blockchain securities. Investors can explicitly program trading rules into the so-called smart contracts. Secondly, peer-to-peer interactions are possible and simple. The third is the option of linking ownership to a public key. This feature allows market participants to contact each other directly and therefore do not have to go through a third party or a separate system. Gaurang Bansal, Mohsen Guizani , Neeraj Kumar, Vikas Hassija, Vinay Chamola (Zhu and Zhou 2016) A quantitative model for stock market analysis is developed using the New York Stock Exchange test dataset to achieve 99.71% accuracy. The model uses a smart contract, and once the agreement's rules are met, the transaction is further processed. The smart contract conducts the verification and execution of the transaction negotiation. Whether an issuer or acquirer wants to sell his stocks or purchase a stock, calling the smart contract triggers a transaction. The name of the company and the number of stocks to be transferred should be mentioned in the transaction. The smart contract then accesses the smart agent, a different entity accessible only via the smart contract, which trains the predictive model using the distributed ledger and forecasts the future. The future forecast is offered to the agent who wants to continue or choose to alter the transactions. When the transaction is completed, it is authenticated as well as logged with the distributed consensus mechanism.

Q4: What are the possible challenges and legal issues of implementing blockchain in the Securities Exchange Market?
The adoption of Blockchain Technology in the Securities Exchange market will bring about a radical change in the industry. Despite the promise that blockchain technology can bring, major legal impediments create uncertainty about its wider adoption in the financial market. The wider adoption of blockchain also depends on its ability to conform to the existing regulatory framework, including many new regulations imposed on financial markets and market participants since the financial crisis.
This section highlights the challenges and significant risks in the adoption of this technology are.
First, we will discuss the major changes that blockchain will bring to the industry and then how to tackle these changes [35].
Blockchain is making many improvements to the trading of securities. The first big improvement in the crypto-securities industry is that it would no longer allow brokers to participate in trades, which gives the traders an advantage indirectly trading through the exchanges or peer-to-peer, thus increasing income. Another big shifts in the position of the transfer agents the market for cryptosecurities could overlook the need for transfer agents. For the proof of ownership, paper certificates will no longer be needed. The blockchain can keep a clear and accurate record of who owns what.
With the use of technology such as colored coins, however, issuers will be able to apply code to the underlying shares that will automatically contain the required restrictions. Unregistered securities can be coded as unregistered, and shares with reselling restrictions can be coded with appropriate reselling restrictions. Hence, there is no confusion about when the owner will sell the shares.
Distributed Ledger technology is built on a highly failure-proof, complicated technological system. The function of a legal framework is not yet completely established, which is one of the major challenges when implementing this technology. Because of the extremely fail-proof blockchain technology, we could be convinced by the scheme of leaving dispute resolution between various users or the engineers of the software platform or by the rules set up already in the platform, since the interference of a state-made legal system might make the platform less practical and efficient.
However, investment companies, regulated banks, etc., cannot afford to transfer large securities portfolios into a platform, which is technically good but is not safe from the regulatory and another legal perspective, which is where the importance of a system of economic control comes in.
As users of the network, the value of acquisitions and securities transactions using the distributed ledger technology goes beyond the sole interests of the seller and buyer. If either -buyer or seller is insolvent, the issue of 'who owns what' would be of vital concern to unsecured creditors.
Commercial and insolvency laws ought to respond. Acquisitions and transactions made on securities replace the whole industry with a single step. It should go step-by-step and replace the entire industry, just like the e-mail, which brought a major change in the postal sector. Similarly, the existing system should also be maintained just like how we retain the postal methods even though we have an e-mail facility [36].
Even though it is an early stage, legislators should take more interest in the regulation and law framework for this new blockchain securities market. The present global securities trading system shows how disintegrated business practice and law can develop. Therefore, national policymakers and foreign organizations should take a constructive approach and develop an effective and legally safe environment for securities instead of being reactive. Early identification of regulatory and legislative participation is also critical, as a legally protected environment would attract only the mainstream sections of the financial sector, which would be the joint work of policymakers, regulators, and the financial sector to achieve the highest potential productivity and liquidity benefits in securities settlement from blockchain technology.

Limitations
There are some limitations to a systematic literature review. Firstly, a systematic review's output is dependent on the accuracy of the included studies. If there are fundamental flaws in the original study's methodology, that flaw will continue in the pooled analysis. Secondly, there is a greater chance that significant and positive research will be published. That means negative or insignificant findings are less likely to be available to the public for inclusion in the systematic review. We checked for peer-reviewed articles on the most important sources and scoured a large pool of information to fix this. Another drawback is the bias in choosing samples, which refers to possible biases due to the parameters used to pick studies and identify the sample population, which may be the product of a badly crafted search protocol. To resolve this, we identified the papers based on a defined set of questions.

Future Research Directions of Blockchain in Securities Exchange Market
Blockchain implementation of Securities Exchange is still in the initial stage of development.
However, in the context of the current studies that we have, we have identified a range of expertise gaps that point to potential study directions. For further inquiry, we are discussing some of the most pressing areas below: After the concept of decentralization using blockchain, we see much conceptual research in blockchain implementation in the stock market. However, the empirical studies are still in the emerging phase. We need more empirical studies about blockchain implementation in the Securities Exchange market to understand the feasibility and understand how much more efficient it can provide than the traditional system.
Since Satoshi Nakamoto publicized the white paper, he proposed Bit coin as a viable peer-topeer digital currency. Research work has increased, and other applications utilizing blockchain technology have emerged. Also, several blockchain platforms have been developed since then.
Ethereum is the most popular one, and others include IBM Blockchain, Eric, and Ripple. However, our analysis indicates that most of the studies in our selected population are focused only on Ethereum. There are many more platforms available, and more empirical studies are required to understand the efficiency of each of these platforms. In addition to this, we need more studies focused on a particular stock market. For example, the Australian current securities exchange, known as CHESS, is replaced by blockchain technology known as ASX private permission ledger designed with high levels of privacy and security. So, depending on the nature of each Stock market, we need to select blockchain platforms. Hence, studies focused on different Stock exchanges, and blockchain platforms suitable for them are required.
Financial markets and the market participants are subjected to strict regulation. These regulations are focused on investor protection, financial stability, and establishing fair and open capital markets. Besides this regulatory structure, blockchain systems, data security frameworks, and regulations also become important. The potential of blockchain technology lies in generating a record of information that participants update and share. Therefore, the legal basis for such documents is vitally important for the widespread adoption of distributed ledger technology. Therefore, we need more legal frameworks-related studies to accommodate record-keeping on a distributed ledger and the current legislation [37]. Table 4 shows summary of future research directions.
There are some limitations to a systematic literature review. Firstly, a systematic review's output is dependent on the accuracy of the included studies. If there are fundamental flaws in the original study's methodology, that flaw will continue in the pooled analysis. Secondly, there is a greater chance that significant and positive research will be published, which means negative or insignificant findings are less likely to be available to the public for inclusion in the systematic review. We checked for peer-reviewed articles on the most important sources and scoured a large pool of information to fix this. Another drawback is the bias in choosing samples, which refers to possible biases due to the parameters used to pick studies and identify the sample population, which may be the product of a badly crafted search protocol. To resolve this, we identified the papers based on a defined set of questions. Potential research agenda 4: By applying blockchain technology, there is an added concern of data privacy and protection that must be added to the existing legal framework. Hence more studies related to legal frameworks that can help blockchain implementation in the securities exchange market are required.

Conclusion
The main objective of this analysis is to map the early stages of blockchain implementation in the Stock Exchange market, how it can resolve the limitation of the existing framework, the current state of the various studies, the different models proposed, and the legal criteria for their implementation. We analyze that the research is still in the early stage, demonstrated by the ratio of conceptual (89%) to empirical articles (11%), which we would presume would be the case for a new theory for scholarships. The studies clearly illustrate that blockchain is a ground breaking technology that can bring a revolutionary shift to securities trading. However, scholars balanced the positive tones by addressing threats and challenges, including technological and organizational obstacles, to a more comprehensive technology application. Altogether, there is a lack of empirical studies and more data-driven studies. While blockchain technology is a very innovative field, the pace of research happening is low. This (Ølnes 2017) article, summing up the latest studies and highlighting the study gaps in those studies, contributes to the early stage of research in the stock exchange market. In this, we help researchers understand the current state of science, recognize gaps in research and serve as a starting point for further study.