This index of 500 large companies doesn't gap down often at all. These are very rare. So this could be a very bearish sign. The MACD and its histogram look bearish too. https://s3-us-west-2.amazonaws.com/maven-user-photos/seanhyman/technical-analysis/IOSU6hIfr0e_ddd3b0bprg/n8qzU9A8LEqN1NIxIj3UGQ
Click on the chart to enlarge it.
Each quarter, the "big boys" in the market have to report their positions because they're so large. Once those reports are made public, it shows what stocks they're adding to or reducing their exposure in and what stocks they've recently bought or completely sold out of.