I find Finviz useful for getting a visualization of the market from its color-coded heat maps. Each stock in the S&P 500 is represented by a square sized according to its market cap.
Below are two charts: the first one shows which stocks and sectors were up the most over the past 3 months, and the second one shows today’s movement. I used this chart to pick up some shares in LLY to add some diversification to my tech-heavy portfolio.
It also has a screener with dozens of factors. Anyone else here using Finviz?