Palantir stock has been on a tear over the last two years, but the company's valuation may be peaking.The allure of artificial intelligence (AI) has dominated the stock market for over two years. AI is not just an interest among investors -- it's become a bit of an obsession. And one stock that investors just can't seem to get enough of is data analytics specialist Palantir Technologies (PLTR 6.77%).As of this writing (April 30), Palantir stock sports a share price of roughly $117 -- just a stone's throw aw ...