AMD (AMD +1.74%) has been a tremendous stock to own in 2026. It has risen about 150% this year, ranking in the top 10 for best- performing S&P 500 (^GSPC -0.52%) stocks. That's an admirable performance, and it has AMD investors believing that it's truly taking ground from primary competitor Nvidia (NVDA -0.59%) in the all-important data center market. However, I think some of this performance isn't earned, and the stock could be ripe for a pullback. There are several factors that point to this potentially c ...