def drop_below(threshold=5, **kwargs):
    """Trigger function that returns True if the price falls below the threshold

    price_today < threshold and price_yest >= threshold
    """
    if (
    #    kwargs['price_today'] and kwargs['price_yest'] and
    #    not np.isnan(kwargs['price_today'] and not kwargs['price_yest'] and
        kwargs['price_today'] < threshold and kwargs['price_yest'] >= threshold
        ):
        return True
    else:
        return False