Friday is quadruple triple witching day in US stocks.
Stock options, index futures, and index futures options derivatives contracts simultaneously expire. There was a 4th type of expiration, single-stock futures, which was never a big contributor, and don’t trade now.
Witching occurs 4 times a year, on the third Friday of March, June, September, and December.
Trading volumes tend to surge on these days, as does volatility, particularly in the final hour or so leading into the close.
Add in it’s a holiday on Monday (June 19) in the US. The New York Stock Exchange and the Securities Industry and Financial Markets Association began observing Juneteenth as a market holiday in 2022.
A heads up for added risk from this.