When checking MSTY's weekly options on Fidelity, I noticed two different contract options expiring on the same day and near the same strike price, with one labeled 'ADJ.' For the contract marked 'ADJ,' the bid-ask spreads for many strike prices were unusually large, sometimes even close to the underlying stock price itself. In fact, 'ADJ' typically stands for 'Adjusted'—meaning the contract has been modified by the exchange due to corporate actions like stock splits, dividends, or mergers involving the underlying asset. Adjusted options differ from standard contracts in terms of liquidity, pricing logic, and exercise rules. Sparse order books and huge spreads are common. What might seem like a 'cheap' strike price is often just a leftover from the adjusted old contract, and you can't simply use the current stock price to arbitrage it. This kind of situation is more common after dividend payouts, ex-dividend dates, or stock splits, especially for high-dividend stocks like MSTY. If regular traders don’t fully understand the adjustment details and jump in recklessly, they might find liquidity dried up when closing their positions or get caught by recalculated terms during exercise.