This behavior is common among illiquid instruments and during nasty times. You can see a couple on GOOG , AMZN , AAPL and others. Now you see it in SPDR. These, are the most liquid assets in the world. This period though, is not nasty. Valuations are going high and political scenarios are less grimey than thought (EU populism, low , stuff like this). This given, gaps that big in the SPY are very not common, thus I am calling for a $260 correction.