After hour T Trade is a market maker accumulating a large amount of a stock in one trading day, that market maker may actually not report any of the trades that occurred until the trading day has ended so as not to alert the market to the collection. This practice is completely legal under the FINRA rules of the OTC Markets so long as the trade is reported at the end of the day.
To execute a Market on Close” order, a market maker may have an order to purchase the stock at a certain price at the end of the trading day. This is the most unlikely scenario because it needs to be assured that someone selling the stock and someone buying that stock are agreeing upon a price. Simply put, this is more likely with insider buying and selling.
The T Trade that the public sees is nothing more than one or all of the above scenarios. The T Trade reported at the end of the day can be from one market maker or many involved market makers. It can be a single purchase price but is usually an average of all of the previously unreported purchases from that business day.
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