How Adverse Selection Varies with Product and Order Entry
Summary
The document asks whether adverse selection after a limit-order fill has a characteristic time horizon. The question describes an immediate price move against the resting order, followed by the possibility that the market later reverses. The response says that adverse selection depends on the traded product and is strongly conditional on how the order was entered, so the initial unfavorable move is not surprising.
It frames adverse selection as a cost that can offset the apparent benefit of improving execution through a limit order. In particular, pegging to the best bid or offer may expose a trader to fills when the quote is stale or informed flow is present, while marketable orders cross the spread. The response gives no study, data, or estimates across timescales, so it does not answer the empirical question quantitatively. Its practical point is that fill outcomes and subsequent price paths need to be evaluated by product and entry conditions rather than assigned one universal adverse-selection horizon.
Key ideas
- Adverse selection depends on the instrument and the conditions surrounding order entry.
- A limit order may be filled just before prices move against it.
- The price can later recover, but the response gives no timescale estimates.
- Improving execution with a pegged quote can carry adverse-selection costs relative to crossing the spread.
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Full text
# Does adverse-selection have a time-frame associated with it? # Does adverse-selection have a time-frame associated with it? When my limit order gets filled, the price almost always moves against me due to adverse-selection. However, given 'enough' time the price may yet move back in my favour. Has there been any study into the extent of adverse-selection at various timescales? ## Answer by madilyn (score 3) https://quant.stackexchange.com/a/46047 No, it varies with product and is heavily conditional on your entry. Your experience is to be expected, adverse selection is often just sufficiently large enough to deter you from improving your execution prices by turning a liquidity-taking strategy into a BBO-pegging strategy, i.e. arbitrage-free between peg order and marketable crosses.
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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.