Catalyst4, Inc., a 10% owner of MapLight Therapeutics, Inc. ($MPLT), bought 1 million shares at $13 each on July 30, 2026, according to a same-day Form 4 filing. The $13 million trade capped a three-day cluster of four open-market purchases worth roughly $15.3 million. After the purchase, Catalyst4 held 20,906,689 shares of the clinical-stage biotechnology company.
The buying spree started on July 28, when Catalyst4 acquired 141,088 shares at $10.74 per share and another 65,137 shares at $11.69 per share, spending about $2.28 million across the two transactions. On July 29, it purchased 3,000 shares at $12.63 per share. The four trades between July 28 and July 30 added 1,209,225 shares to the entity’s position.
Before the buying, $MPLT shares had cratered. The stock closed at $36.56 on July 24. By the close of July 27, it was at $9.91, a single-session plunge of roughly 73%. The shares then rebounded to $12.31 on July 28 and $15.02 on July 29, according to daily price data.
Catalyst4 last bought $MPLT shares on October 28, 2025, when it acquired 5,441,176 shares at $17 per share in a deal worth $92.5 million. That purchase lifted its reported stake to 19,697,464 shares.
Insider transactions told another story. Multiple MapLight Therapeutics officers and executives reported open-market sales during May and mid-July 2026, at prices ranging from about $27 to $38 per share. CEO Christopher A. Kroeger sold shares on May 5 through May 8 and again on May 11, offloading tens of thousands of shares. CFOs Jonathan Gillis and Vishwas Setia, Chief Discovery Officer Anatol Kreitzer, Chief Scientific Officer James Woodruff Lillie, Chief Medical Officer Erin Pennock Foff, and General Counsel Kristopher Hanson also filed sales. Among them, Gillis and Kreitzer were the most active sellers in the July 15 through July 17 window, each filing multiple Form 4s at prices between approximately $36 and $39 per share.
MapLight Therapeutics had a market cap of roughly $1.5 billion. No members of Congress disclosed trades in $MPLT during the period, based on a review of STOCK Act filings.