Peter Thiel has sold nearly $600 million worth of Palantir Technologies Inc. (NYSE:PLTR) stock this week, according to the company’s regulatory filing with U.S. Securities and Exchange Commission. This brings his total stock sales for the year to over $1 billion. What Happened: Thiel sold more than 16 million shares over a span of three days this week. This adds to the 20 million shares he sold in March and May, according to the SEC filings. The filings did not specify the reasons behind Thiel’s stock sales or his plans for the proceeds. Thiel, who co-founded Palantir and has a fortune estimat…