Plug Power (PLUG -5.17%) signed another seemingly impressive supply agreement with Amazon (AMZN -2.56%), continuing a relationship that goes back to 2016. This video goes into how Plug Power has performed since it became an Amazon partner and why investors should beware. 

*Stock prices used were the end-of-day prices of Sept. 2, 2022. The video was published on Sept. 6, 2022.