Magna is a company. They open accounts with stock brokerage firms. When they place a sell (or buy) order with their broker, the broker enters the order with the OTC Department. The firm will either act as a Market Maker (if they are an approved MM for the stock) or act as agency (if they're not MM for this stock) which means they will use an MM for the transaction.
Yes, Magma uses the same process as YOU when buying or selling STOA. They are not MM's.
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