A “coordinated effort” is not legal. That is price manipulation. Such acts are picked up fairly easily in surveillance reports, investigated and prosecuted. It is not at all uncommon for a stock price to be “pinned” to an options strike price with large open interest. That happens from many traders using the same strategy, especially at expiration. Back in the 1900s, expiration was only once a month, Now expiration is every Friday in many names, especially active names like TSLA. You don’t say how long the price is held at some level. It would not be at all odd for a price to be held for a portion of a trading day if an institution is filling a very large order.