Large speculators and other heavyweight investors have been eager to buy the dip during the stock market's stormy October. One group that hasn't: executives in charge of U.S. companies.

Corporate insiders, whose buying correctly signaled the bottom in March, have refrained from bargain hunting this time. Fewer than 380 corporate executives and officers snapped up shares of their own firms last month, the second-lowest showing in at least two years, according to data compiled by the Washington Service. While sellers also retreated, they did so at a slower rate than buyers. As a result, insider purchases trailed sales by the most since January.

This behavior is at odds with the behavior of commercial traders grouped under the Commodity Futures Trading Commission (CFTC) category "large speculators," who have boosted their net positions in S&P 500 e-mini futures to the highest level since January 2019.