Theoretically if what you heard was true, they would be blocking the purchases using margin (credit).
Based on what I've read, it looks like they suspended purchases regardless of if it was margin (credit) or your using own money in the account.
Not sure if there's any fine print in Robinhood's terms and conditions regarding blocking purchases (but not sales) of publicly traded companies or not....
Seems like they're trying to prevent further market manipulation... by using market manipulation.
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