Arbitrage-free price refers to the price at which no price arbitrage is possible. This strategy is categorized as a statistical arbitrage and convergence trading strategy. Scalping is not actually arbitrage, but short term trading. It belongs to wider categories of statistical arbitrage, convergence trading, and relative value strategies. The currency carry trade is an uncovered interest arbitrage. Corporate transactional events generally fit into three categories&colon; distressed securities, risk arbitrage, and special situations. Competition in the marketplace can also create risks during arbitrage transactions. AMC is the first known attempt at computerized arbitrage trading. Such price differences only create efforts by market participants to arbitrage the difference. In comparison to the classical quick arbitrage transaction, such an operation can produce disastrous losses. It is in principle the same as the arbitrage using different bookmakers. The potential revenue from this arbitrage can offset the cost and losses of storage. Such possibilities put the risk in the term risk arbitrage. Risk "arbitrage" is not risk-free. In the extreme case this is merger arbitrage, described below.