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Innovation in stock trading delayed at the SEC 

In today’s stock market, the large stock exchanges often brag that spreads have never been lower and commissions have never been cheaper. The popular investing app Robin Hood even offers free trading, as do E-Trade and Charles Schwab. The part of the story they don’t like to mention is the hidden tax on trades common in the market known as latency arbitrage.

This is a practice that some exchanges facilitate for their high-speed trading clients in which these speedy computerized traders are sold high-speed, digital information about the direction of stock prices. They use this high-speed information to pick off unsuspecting investors and thereby profit at the expense of the other order.

This latency tax is costly. British financial regulators recently estimated that latency arbitrage costs investors $5 billion per year globally. Professor Marius-Andrei Zoican describes the problem this way: “The presence of latency arbitrage leads to a zero-sum race in trading execution which negatively impacts liquidity and harms execution quality for retail investors.”

The trader does not know he/she is third in line, just behind the broker.

The problem goes away with bearer digital assets, we can leave our bot in the pits and it is guaranteed a fair traded pi. 

I dunno what the SEC's problem is.  But look at something like Coinbase trader, an automated, asynchronous binomial match machine.