One of the hottest nuclear stocks took a beating this week. Here's why.Shares of Oklo (OKLO -7.40%) fell this week, finishing down 18.3%. The drop comes as the S&P 500 and the Nasdaq-100 Composite lost 0.3% and 0.5%, respectively.The advanced reactor developer's stock is getting battered this week after a research note from Goldman Sachs cautioned investors not to get ahead of themselves. The company also saw significant insider selling this week.Goldman initiates coverage of Oklo stockAmid significant inve ...