This valuation metric points to more upside for these tech stocks.Nvidia (NVDA -1.59%) and Meta Platforms (META 0.40%) have rocketed higher this year. But these companies are benefiting from powerful trends in data center spending and digital advertising that could send their share prices to new highs in 2025.These stocks trade at relatively low forward price-to-earnings (P/E) ratios compared to Wall Street's 2025 earnings estimates, which could set up another monster run for investors next year. Here's how ...