Check out the companies making the biggest moves in premarket trading: Tesla — The electric vehicle maker tumbled 6% after CEO Elon Musk said he would form a new political party called the "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 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 effects 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 it to buy from a hold rating. The Wall Street firm believes the sell-off has gone too far, and said the recovery should accelerate, driving upside. Jefferies pointed to its wine business that is turning profitable, strong cash flows and buybacks. WNS Holdings — Shares jumped 14% after French multinational company Capgemini said it will acquire WNS in a $3.3 billion cash deal. Capgemini is paying $76.50 per share, a 17% premium to Wins' closing price on July 3. Shell — U.S.-listed shares of the oil and gas company slid nearly 3% after Shell said it expected weaker gas trading would hurt quarterly earnings. The company is due to report its second-quarter results on July 31. MGM Resorts International — The casino stock lost 2% after Goldman Sachs initiated coverage with a sell rating. The bank said it expects pressure on MGM's free-cash-flow generation to weigh on capital returns and valuation. — CNBC's Jesse Pound and Yun Li contributed reporting.
