Billionaire investor Mark Cuban warned Thursday on CNBC’s “Squawk Box” that Vice President Kamala Harris’ capital gains tax plan would “kill the stock market.” Cuban said, “What I told them is if you tax unrealized gains, you’re going to kill the stock market, and it’s going to be the ultimate employment plan for private equity because companies are not going to go public because you can get whipsawed.” He added, “Based off the unrealized gains, I would have had to borrow money and I effectively would have been in hawk just to pay my tax bill instead of trying to...