I been trying to find the exact answer/ definition of those trades but it happens every day with every big board stock with lots of volume.
i cant find the post but i couple years ago two posters on some other board were arguing over your exact question.
if the 9M trade went through at any time during 9:30am and 4:00pm it would likely have been a major institutional buy or someone taking a major stake, but because the trade likely printed immediately after close of regular trading hours, 99% of the time, it would fall into the other category in which the aforementioned argument i mentioned was about.
if you want a true answer, call your broker. They can probably give you the exact answer.
more often then not, a trade of 9M if in one true block, would likely be found/coincide with an updated SEC form 13F
9,000,000 x $59.00 is is $531,000,000
if that were a buy to force AMC above $60, why not place the order for $60.10? it would have easily taken out all sell orders
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