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Comment by sgt101 | Hacker News Reader

If I was regulating the markets I would introduce a random ~100ms delay into all transactions.

The IEX stock exchange uses fibre to introduce a fixed delay - https://en.wikipedia.org/wiki/IEX

"This 350 microsecond delay adds a round-trip delay of 0.0007 seconds and is designed to negate the certain speed advantages utilized by some high-frequency trader"

I watched this short video about it too - https://www.youtube.com/watch?v=d8BcCLLX4N4

The company who has the best latency would still beat the competitors.

Are you sure about that? They would on average perhaps be a slight bit faster, but if the randomized delays are an order of magnitude larger than the latency, they may not be able to do anything useful with that advantage.

wouldn't it be like this?

If the delays are randomized then you have as good as chance of getting them as your competitors. On delayed times you will have a bad chance of winning, but in comparison to others with the same delays your latency beats theirs, on non-delayed times your latency beats non-delayed competitors and really beats delayed competitors.

Thus in the end the best latency should win biggest on non-delayed trades, and on delayed trades lose least.

Unless that uncertainty now means that your time and resources is best spent elsewhere than shaving ms off your latency.

Well, think through some toy examples. Suppose there is a market without order matching (again, toy example) and one market participant enters an extremely mispriced order, so the first person to fill that order wins. Even in the presence of random delays, the participant with the lowest-latency connection has a higher chance of filling the order than anyone else. (There are other anomalies, e.g. participants are now incentivized to have as large a number of distinct connections and hence "chances to roll low" on the randomized delay as possible).

They could collect all issued transactions in a ~100ms time window, process them in a randomized order, and publish new prices after that.

This mechanism ("batch auctions") are not immune to rewarding low-latency connections. The details depend on the exact auction mechanism but the general idea is that you want to join the batch as late as possible (at any moment in time when you make a decision to join the batch, you are never worse off if you wait a while before joining) and low-latency connections can afford to join later.

In fact with your exact proposal, assuming everyone has a connection with at most (say) 50ms latency, no one will join the batch in the first 50ms, which (I think) magnifies the low-latency advantage.

So randomize the batch window length as well then, say 10-100ms.

If you make a decision to join in the (say) the 5th ms of the batch auction and you have a latency of 1ms, you are still no worse off if you decide to wait 4ms before joining the batch.

You can solve for this with a commit and reveal scheme, where trades with hidden price and size are committed in the first period and revealed and settled in the second period.

The advantage of speed or waiting until the end is mitigated as you can receive no additional information either way.

The way it is now the company that's invested the most in communications and is better located wins. Meritocracy is good.

I can only assume that either you are being sarcastic, or you haven't got a pension - because if you have I can tell you, your pension is being used to pay the winnings.

Why would you do that?

To negate market advantage created by investment and monopoly practices; HFT is front running, front running damages the economy, but more importantly it damages me because I can't do it and therefore it is just being done to me.

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