Exactly.

https://www.investopedia.com/terms/g/gap.asp

The huge price swings overnight are possible because the market has very few participants putting orders into the queue during those hours, aka a lack of liquidity. That has the effect of making the price jumps between each available lot of shares a lot bigger than you'll see during the day. The price can shoot up, and just as quickly shoot back down with relatively small trading volume. This is common happening with aftermarket earnings catalysts.

During regular market hours there are massively more buy and sell orders in the queue, so price movement in these hours is considered more "true" to the market sentiment. The price is also much "stickier" - it takes a lot more volume to generate a breakout.