Palantir and SpaceX are both up around 40% since August, but analysts are warning about their high valuations. Palantir had a strong Q2 with revenue up 93% to $1.9 billion and earnings up 156%. Jefferies noted they might not be investing enough in the business compared to competitors. PLTR is currently trading at 68 times sales, making it the most expensive stock in the S&P 500. SpaceX's Q2 revenue grew 92% to $7.8 billion, mostly driven by their AI segment and renting compute to Google and Anthropic. However, they reported negative free cash flow of $25 billion for the first half of 2026. Morningstar warned the stock is priced for perfection at 94 times sales, leaving little upside and a risk of a significant price drop.