I'm going to go out on a limb and say it stops today, and in a big way!
As the market pulls back today, a large trade is positioning for another drop in the S&P 500 in the next two weeks.
optionMONSTER's Depth Charge system shows that a trader bought 5,853 April 1365 puts for $0.40. The volume was 4 times the strike's open interest before the session began, so this is clearly a new position.
Those puts are more than 11 percent out of the money --a sizable amount, given that these contracts expire in only two weeks. But they have a delta of just 0.01, suggesting just a 1 percent probability that they will be in the money by that April expiration.
This could be an outright bearish bet but is more likely hedging against a long portfolio. Many traders buy puts in indexes as an alternative to protection on individual names, especially when they are concerned about a broader market decline. (See our Education section)
The SPX is down 1 percent this morning to 1543, on pace for its lowest close in a month. The index was last below 1365 in mid-November and posted an all-time closing high of 1570 on Tuesday.