Check out the companies making the biggest moves in premarket trading: Tesla — The E.V-maker tumbled 6% after CEO Elon Musk said he would form a new political party called “America Party.” Musk has been engaged in a feud with President Donald Trump, who called the new party “ridiculous.” Geo Group , CoreCivic — The private prison companies gained 7.6% and 5.4%, respectively. Trump’s so-called big, beautiful bill spending and tax cut bill, signed into law on July 4, includes a significant increase in funding for immigration detention centers. Molina Healthcare — The managed care stock gained 1% after Molina’s CEO said the potential impacts of the budget bill being considered in Congress do not change the long-term outlook for the company. However, the company did say it now expects adjusted earnings per share of $5.50 in the second quarter and from $21.50 to $22.50 for the full year, which is down from prior guidance. Molina cited “medical cost pressures” for the reduced outlook. SolarEdge Technologies — The solar company shed 2.8%. The stock jumped 39% the week prior after a tax on solar and wind projects was removed from Trump’s spending bill. However, the law removed federal support for solar and wind power. Constellation Brands — The booze stock gained about 1% in premarket trading after Jefferies upgraded …