[stouset]

What is the value of trading at increasingly marginally more accurate prices? And more importantly, what is the cost?

You seem to take it at face value that trading at accurate prices is an unalloyed good. But for the extremely overwhelming majority of retail investors — whose only sane strategy is buy and hold — buying at a few tenths of a percentage points closer to the most-accurate possible price is worth nearly nothing (and has negative worth half of the time, practically by definition).

On the other hand, Wall Street has been raking in tens if not hundreds of billions in profits from this service. What value we get from more accurate pricing may very easily be offset by these costs a hundredfold.

[harryh]

You are drastically overestimating how much money HFT market makers earn. Virtu Financial (one of the biggest firms in this area) earns about 100 million a year.

I think you are also underestimating the costs to retail investors to not getting accurate pricing. Shaving a few tents of a point off of every trade will have a huge effect on the lifetime earnings of an individuals.

[snark42]

> earns about 100 million a year.

They made 147M in the first quarter of this year. 197M in the first quarter of last year. They might only make 100M/year after costs, but that doesn't represent the 600-900M they take from the market.

[dsacco]

That's not the point. The point is that the industry is vanishingly small compared to Wall Street proper, yet it has an outsize target on its head due to FUD and emotional appeals like the ones presented in the article.

Furthermore, in exchange for "taking" that money from the market, they enhance liquidity, which is directly helpful for price discovery and facilitating trading among both retail and institutional investors.

People are continually moving the goalposts in this thread and others like it. If you're going to talk about Wall Street and fraud, high frequency trading is not the place to start. All of the legitimate arguments against high frequency trading have nothing to do with fraud, they have to do with the dangers of runaway algorithmic trading that coalesces into the same market movements.

But we can't reason about that issue while half the people talking about HFT (almost none of whom actually have experience with trading whatsoever) still think it's front running, or believe it constitutes some sort of fraudulent con over "the little guy."

[concede_pluto]

Liquidity is willingness to make a trade others aren't. To be useful, it has to linger in the order book for a long time. If you're winning a race by milliseconds, you are trying to interpose yourself into a trade that was already going to happen that day.

[dsacco]

> If you're winning a race by milliseconds, you are trying to interpose yourself into a trade that was already going to happen that day.

This is an inaccurate framing of how high frequency trading propagates liquidity in an otherwise illiquid (or strictly less liquid) market. The claim is not that liquidity is contributed on a strictly trade by trade basis, but rather than the low-latency activity has meta-reactive effects owing to enhanced price discovery that increase overall participation by drawing in other traders at different time resolutions. For example, where there may a stagnant order book on one equity (and consequently, few human traders able to fulfill orders without significant pricing penalties), the same order book may draw in competing market makers. They attempt to predict the next price movement - some win and some lose on the immediate sequence of trades, but the consequent activity narrows the bid/ask spread by heightening local participation in the order book and improving the pricing confidence. This has practical ramifications for "human" time resolutions, because the human traders now have a better opportunity to fulfill orders without overpaying. This in turn reduces overcautious traders from participating, and so on and so forth.

For what it's worth, your line of argument has been rehashed for years now on Hacker News, going back to when Chris Stucchio wrote his HFT apologia. Instead of lazily linking to that thread, I'll do one better by walking through research on the subject. Fortunately there is a handy paper that explicitly examines the question, "how does the interaction of these traders in the millisecond environment impact the quality of markets that human investors can observe?"[1] The data is constructed using NASDAQ TotalView with equities in the S&P500 in periods of varying volatility. Both reactive and periodic trading algorithms are reviewed.

Here are a few critical passages:

By tracking submissions, cancellations, and executions that can be associated with each other, we create a measure of low-latency activity. We use a simultaneous equation framework to examine how the intensity of low latency activity affects market quality measures. We find that an increase in low-latency activity lowers short-term volatility, reduces quoted spreads and the total price impact of trades, and increases depth in the limit order book.

IV.B. Results Panel A of Table 4 presents the estimated coefficients of the pooled system side-by-side for the 2007 and 2008 sample periods. First we note that the two instruments have the 25 expected signs and are highly significant. Specifically, the coefficient a2 indicates that when liquidity off NASDAQ is higher, our NASDAQ market quality measures show higher liquidity and lower volatility. Similarly, the coefficient b2 is positive in all specifications, indicating that higher low-latency activity in a specific stock in an interval is associated with higher low-latency activity in other stocks on the NASDAQ system. Second, the estimated b1 coefficients tell us that low-latency activity is attracted to more liquid and less volatile stocks.

The fact that low-latency trading decreases short-term volatility and contributes to depth in the 2008 sample period where the market is relentlessly going down and there is heightened uncertainty in the economic environment is particularly noteworthy. It seems to suggest that PA activity creates a positive externality in the market at the time that the market needs it the most. Panel B of Table 4 presents roughly similar results from the estimation of the system with SpreadNotNasi as the instrument for market liquidity.

It is possible, however, that the impact of low-latency trading on market quality would differ for stocks that are somehow fundamentally dissimilar, like small versus large market capitalization stocks. Table 5 presents system estimates in subsamples consisting of four quartiles ranked by the average market capitalization over the sample period.22 There is not much pattern across the quartiles in the manner low-latency activity affects short-term volatility in the 2007 sample period. The picture in the 2008 sample is different: It appears that during more stressful times, low-latency activity helps reduce volatility in smaller stocks more than it does in larger stocks.

Lastly, Table 6 shows summary statistics for the stock-by-stock estimations. The results suggest similar conclusions concerning the effect of low-latency trading on market quality. In particular, an increase in low-latency activity decreases short-term volatility, decreases quoted spreads, and increases displayed depth in the limit order book. This is true both in the 2007 and 2008 sample periods.

_______________

1. http://people.stern.nyu.edu/jhasbrou/Research/Working%20Pape...

[auntienomen]

OK, so gross-not-net, Virtu is making about $2M/day. The value traded on a typical day in US stock markets is north of $100 billion / day.

HFT is rounding error.

[snark42]

> Virtu is making about $2M/day. The value traded on a typical day in US stock markets is north of $100 billion / day.

You can't estimate it that way as they don't win or profit on all their trades. At it's height HFT was estimated to responsible 15-25% of daily volume by best guesses (it's some what obfuscated.) I'd be surprised if it was less than 5% today. Not just Virtu of course - all players big and small.

[vostok]

Why does this change whether or not you can estimate it that way? The tick size in the US is at least $0.01 for reasonably priced names so it's completely unrealistic to expect an HFT to make money on every trade.

When people talk about making $0.0001 per share that's their ex-ante expectation. It accounts for the fact that you're not going to make money on every trade.

[vostok]

Do you think Virtu takes more or less money from the market than the market makers they displaced?

[uiri]

If one is employing a buy and hold strategy, then it doesn't make sense to perform buy operations for every pay cheque. At the level of a retail investor, making buy trades once a quarter or once a year will do far more for a retail investor looking to have money on market making operations.

A few tenths of a percent is on the order of less than $100/year assuming that a retail investor invests the maximum amount allowed inside a 401k each year (ignoring for a second that typical 401k plans do not permit investing directly in individual stocks and also ignoring catch up contributions for older folks). It's just not a significant amount of money at the level of an individual retail investor.

[rramdin]

Automating the work done by human traders, market makers, and specialists has not only facilitated decimilization resulting in smaller spreads, but also allowed trading fees for the retail investor to reach historic lows (the worst you'll find at a retail brokerage nowadays is about $8/trade, far better than the $35/trade), with many even being free. Wall Street had always been raking in billions in profit from market making activity, if anything that profit margin has been significantly reduced by automating market making.

[stouset]

> ...also allowed trading fees for the retail investor to reach historic lows (the worst you'll find at a retail brokerage nowadays is about $8/trade, far better than the $35/trade

The average retail investor should not be making enough trades for this to matter.

Bringing down the price of trades like this only makes it cheaper for the suckers — day traders — to think they're playing the game. It is of marginal utility for the average retail investor.

[URSpider94]

That's not a fair assessment. Let's say you are doing well and actually investing $1000 per month into the market. Now let's say you are diversifying into three index ETF's, and you buy those quarterly, so that's three trades a quarter on a total of $3,000. If the commission is $35/trade, you are being taxed 3.5% of your investment up-front to get into the market. If the commission is $4/trade (a more typical fee these days), then the up-front loss is 0.4%. You'll pay those same fees again on the way out, and assuming that you sell on the same schedule, that's now 7% vs. 0.8%.

Yes, there's some nice compounding in between, assuming that you buy and hold with no further trades. But, there's a wide gulf between "day trading" and active stock-picking. Assuming that your average hold time is 5 years per stock, you're still going to rack up a lot of commission costs at $35 per trade.

[pdeuchler]

There's no real problem at all to professional investors, they will figure out how to trade at the price they want regardless. It mostly hurts retail investors who rely significantly more on market signals to be correct. Professional investors almost prefer inefficient prices as it provides more opportunities for arbitrage against dumb money.

[rtx]

Whats wrong with them making money from their efforts.

[corporateslave3]

Completely delusional about Hedge Fund profitability.