Exchanges have breaks in place and can halt trading for certain stocks. I think it made sense to halt trading given what happened yesterday. But it's not Robinhood's job.
That's a very bad analogy. Exchanges can halt trading. They can say: hey, some crazy stuff is going on here, everyone take a 15 minute time out to think about it before you continue.
Robinhood prevented buying. That is very, very different than stopping trading. While Robinhood's action might not legally be 'market manipulation', it certainly does result in the market being manipulated. People who were not using Robinhood would have their PnL significantly affected since a lot of pressure on the stock price was coming from buyers on RH.
This is _very_ different. They halted _only_ buying, and if I wanted to buy via another brokerage I would need to wait 5 days for funds to clear in Robinhood before I could even withdraw. So they effectively shut off demand but kept supply the same, and there is absolutely no other result that can occur other than the price tanking.
To be clear, Robinhood did not "halt trading" on these stocks, they disabled buying while allowing users to still sell shares. This effectively encourages users to sell.
