Insiders Sell Into Strength, Buy the Dip

Insiders at some of the US market's biggest recent winners are cashing out. AppLovin shows the most negative insider open-interest momentum among large-cap US stocks over the past month. Executives have been selling as the ad-tech stock sits 61% below its start-of-year price, a rare pattern where selling accelerates into weakness rather than strength.

Quanta Services and W.W. Grainger follow close behind on the net selling list. Quanta is up 37% year-to-date, making insider disposals there a clearer case of profit-taking near highs. Grainger has gained 33% over the same period.

On the buying side, Lennar stands out. The homebuilder has attracted the largest volume of open-market insider purchases among mid-to-large US names in the past month. The stock is down 17.7% year-to-date, giving buying insiders a discounted entry point. Corebridge Financial and Kodiak Sciences also saw notable fresh insider buying.

In biotech, ORTEX alt data flags Zenas BioPharma separately: clinical trial completion date slippage moved 2.2 standard deviations below its own history as of 13 October, pointing to an unusually sharp schedule acceleration. Fresh insider purchases in that context would carry added weight.

Meanwhile, the ORTEX Index Rebalance Radar flags Twist Bioscience as a potential Russell 1000 addition candidate, with forced buying estimated at $529 million if it crosses the deciding price of $162.62.