HFT Liquidity Detection Through Small-Order Pinging

Summary

The document describes pinging: sending small orders into a market to infer whether larger resting orders may be present. A quick fill is presented as a possible signal that deeper liquidity is behind the displayed or encountered order. The original question asks whether pinging means measuring the delay between sending an order and its appearance in the limit order book; the answer does not develop that interpretation or give a precise measurement procedure.

The response argues that pinging has become outdated and that its information content is now close to zero because competing algorithms can detect and exploit such probes. It offers no empirical results or detailed market data to substantiate that assessment, so it should be read as a practitioner’s opinion rather than a demonstrated conclusion. The answer also points to paid access to specialized order types as a possible source of advantage, framing this as part of an ongoing contest among firms, exchanges, and regulators. The discussion is brief and does not specify venues, order types, or conditions under which small-order probing might still be informative.

Key ideas

• Pinging uses small orders to probe for larger resting liquidity.
• A rapid fill may suggest that additional liquidity is present behind the immediate execution.
• The answer characterizes pinging as outdated and its informational value as very limited.
• The discussion presents specialized order types as a potential source of HFT advantage.

Tags

# Liquidity detection based strategy in HFT


# Liquidity detection based strategy in HFT












This article contains the following statement.

> In terms of liquidity detection, traders intend to decipher whether there are large orders existing in a matching engine by sending out small orders (pinging) to seek for large orders. When a small order is filled quickly, there is likely to be a large order behind it.

Am I right to suppose that by pinging the mean difference between the time of sending the order and time of posting it on LOB? Or maybe it's something else?

## Answer by Matt Wolf (score 1)

https://quant.stackexchange.com/a/7093

With all due respect, the referenced pdf is nothing but a glossy write up of standard terms that you even hear about on TV nowadays, not much more. I assume its targeting totally uninformed clients (Japanese buy side funds? ;-) who in 2012/2013 still have not caught on with algorithmic execution.

"Pinging" is so outdated that I would claim the information content you derive from shooting small orders into the market in expectation of learning about larger orders looming is gonna be close to zero. We have reached a stage where predatory algorithms have become pray to even more intelligent bits and bytes. The biggest edge I see a hft algo can currently gain over others is paying cash in exchange for "special new" order types. Its another way of letting big spenders gain an advantage over others who are not willing to pay up. Its the same regulators-chase-hft-firms/exchanges-to-fill-loopholes game that has been played for close to 10 years now.

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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.