How does overnight trading work? I don’t understand BUD’s movement before open yesterday.

I had 56 & 55 puts on BUD at market close yesterday and was really excited to see if they print because the 55 put was ITM and 56 put was so close to being ITM. It feels like BUD just magically opened at 57+ and I’m curious how that works? I never saw any charts or candlesticks to suggest the bullish open. What am I missing here?