When trading during major forex-related news releases (like NFP and friends), a significant increase of spread may occur, some tutorials say. As I understand it, even if I've got a stop-loss order in place (or any other event-triggered order for that matter), it might be filled at significantly different prices to my disadvantage.

In all likelihood, this varies from broker to broker. Probably for that reason the first hour of googling didn't give me an idea, what such offset could be (is it called "slippage"?), statistically, at a major news event. Neither historical data nor paper-account won't help here, so my question is: what is your personal extreme experience with the difference between stop-loss order and the actual outcome?

I'm using Interactive Brokers / IDEALPRO.


In my experience thanks to algorithmic trading the variation of the spread and the range of trading straight after a major data release will be as random as possible, since we live in an age that if some pattern existed at these times HFT firms would take out any opportunity within nanoseconds. Remember that some firms write algorithms to predict other algorithms, and it is at times like those that this strategy would be most effective.

With regards to my own trading experience I have seen orders fill almost €400 per contract outside of the quoted range, but this is only in the most volatile market conditions. Generally speaking, event investing around numbers like these are only for top wall street firms that can use co-location servers and get a ping time to the exchange of less than 5ms.

Also, after a data release the market can surge/plummet in either direction, only to recover almost instantly and take out any stops that were in its path. So generally, I would say that slippage is extremely unpredictable in these cases( because it is an advantage to HFT firms to make it so ) and stop-loss orders will only provide limited protection.

There is stop-limit orders( which allow you to specify a price limit that is acceptable ) on some markets and as far as I know InteractiveBrokers provide a guaranteed stop-loss fill( For a price of course ) that could be worth looking at, personally I dont use IB.

I hope this answer provides some helpful information, and generally speaking, super-short term investing is for algorithms.


Slippage is tied to volatility, so when volatility increases the spread will also increase. There is no perfect formula to figure out slippage but from observations, it might make sense to look at the bar size in relation to previous bars to determine slippage (assuming fixed periods). This is because when there is a sudden spike in price, it's usually due to stop order triggering or a news event and those will increase the volatility dramatically in seconds.

protected by Chris W. Rea Oct 23 '17 at 11:03

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