That's what happened. Market makers pump up the share price in the premarket or in the after hours, then short it at artificially inflated prices to everybody in the morning.
Think of it like an investment. You buy $2 million worth of stock for, let's say $25.00, then sell $20 million worth of stock for $26; then you cover when the price tanks in the morning. Of course nothing is guaranteed and it could go wrong, but the risk reward is very strong
Those figures could be an exaggeration because I've never done it before and nor am I a market maker, but you get the jist.
Nobody knows that by the way. Just letting you know. I found that out by pure chance, and maybe by the grace of god.