buy/sell doesn't matter, a T trade is volume that happens during the session but is not reported until after hours, so the trades happened during the day, MM's just aggregate together and post it after hours.
On the OTC T-Trades mean dilution as you will very rarely see T trades without dilution especially is volume is tame overall. You can see t trades if there is a severe volume spike and a massive amount of trades but almost always it is dilution. Add in there are toxic MM's all over the ask and you have clear signs of dilution.
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