bone is probably right about timeframe, though any intraday strat is subject to the whim of the bots to some extent.
so Themis Trading doesn't want a transparent market, they don't want other market participants to have a picture of the true supply and demand for stock because it takes away from their business of charging customers 10-20 x's more in commissions for block transactions combined with heavily discounting blocks so they can take a piece of the action, and reduces their inside information on what the true supply and demand of the stock is, which allows them and their clients to maintain an information edge and make more money. transparency and splicing orders reduces market impact and knowing what the true supply/demand picture are vital to lowering costs, enhancing liquidity, and determining the fair market value price of an instrument. naturally, large buyers and sellers are generally assumed to have better information, and hence, one reason participants monitor that line of data - high frequency trading simply moves prices to the equillibrium value quicker, less expensively, and with less market impact - deteriments to Themis' profits. those arguing for a less transparent market and less high frequency trading and less liquidity, are effectively arguing for a less fair and a bifurcation of prices vs equillibrium prices, where only a priveleged few like Themis have a true picture of the supply and demand. transparency and electronic high frequency trading are a good thing for liquidity, price discovery, and determining the fair value of an instrument. it's not good for institutitonal brokers and those who want to maintain an information edge over other participants. why one would argue for others to be able to maintain that inside information over yourself and the rest of the market, and that would somehow lead to a better fair market value/equillibrium price is perplexing