Risk pooling means they put a lot of people with independent or low-correlated risk into a pool and reduce the risk for the whole pool.

风险汇聚即,将独立或相关性小的风险汇聚起来,以降低整体风险

耶鲁公开课 - 金融市场课程节选

Suppose we had a lot of different stocks that we could put into a portfolio, and suppose they're all independent of each other-- that means there's no correlation.

假设我们现在有很多只不同的股票,可以放进我们的投资组合里，同时假设它们都是相互独立的-,也就是说它们之间没有相关性。

耶鲁公开课 - 金融市场课程节选