Long Island hedge-fund magnate Robert Mercer dumped $11.1 million into Texas Sen. Ted Cruz’s campaign coffers, according to federal filings released Friday.

A former computer programmer at IBM, Mercer earned his wealth designing algorithms to outsmart the stock market and has kept a low profile while cutting checks for conservative causes since 2008.

Nearly a third of Cruz’s $37.8 million haul came from Mercer alone.

Business titans Ronald Perelman, Warner Music Group owner Len Batavnick and former hedge-fund manager Julian Robertson, along with philanthropists Steven and Alexandra Cohen, have also plunked more than a million dollars each to support Republican presidential hopefuls.