Vista Energy shares rose 5.67% to $72.18 on Monday after Thiel Macro LLC disclosed roughly 1.2 million American depositary shares in the Argentine shale producer, a stake worth about $76 million as of June 30, 2026 that made Vista the fund's second-largest disclosed holding after Amazon. The filing showed Thiel Macro rebuilt a $418.7 million disclosed U.S. equity portfolio after reporting no holdings in the previous two quarters, with most new positions concentrated in energy and utility names, while Vista remained the only non-U.S. investment. The bet adds to attention on Vaca Muerta, where Vista operates as Argentina's largest independent energy producer, and comes as President Javier Milei's deregulation drive and Thiel's meetings with senior administration officials sharpen investor focus on Argentine natural-resource assets.