Usually when there is an after hours trade that is way off, the assumption is that it was an order during regular hours that was recorded late.
It had been some hours before close that it last traded at $238, so I don't think that can be the explanation.
@toyolla2: A limit order is straightforward; if the order can be filled at the limit you specifiy (or better), the trade will happen, otherwise it will wait. So if you say "sell at $238", if there are buyers who are prepared to buy for that (or more) the trade will happen.
A market order is paradoxically less straightforward. If you look at the quoted prices, there's a bid (the price at which someone will buy) and a offer (the price at which someone will sell), and they're never the same! That's because if they were the same, the transaction would have happened already. When you place a market buy (resp. sell), you are saying that you will accept the offer (resp. bid) that's currently outstanding. But by the time your trade gets to the top of the queue, those numbers might have changed. This is particularly true of thinly traded stocks and after-hours trades. But even during normal hours it can happen. Suppose you put in a market buy order for 100 shares, and there's someone else (the lowest offerer) offers 10 shares at $238. So you buy 10 shares at $238. But the next lowest offerer had his sell order at a limit of $245! Oops, you will instantly buy as many (up to 90 shares) of his as you can... at $245.
There are people who place ridiculously out-of-the-money limit orders after hours, or on thinly traded stocks, in the hopes that some chump will come along and place a market order that will get filled at the ridiculous price. This is why market orders are not allowed out-of-hours. But there are still occasionally people who will decide that they really want the shares NOW, and will buy them anyway.
I have no idea what happened in this case, but that is my explanation... and I almost never place market orders any more.
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Usually when there is an after hours trade that is way off, the assumption is that it was an order during regular hours that was recorded late.
It had been some hours before close that it last traded at $238, so I don't think that can be the explanation.
@toyolla2: A limit order is straightforward; if the order can be filled at the limit you specifiy (or better), the trade will happen, otherwise it will wait. So if you say "sell at $238", if there are buyers who are prepared to buy for that (or more) the trade will happen.
A market order is paradoxically less straightforward. If you look at the quoted prices, there's a bid (the price at which someone will buy) and a offer (the price at which someone will sell), and they're never the same! That's because if they were the same, the transaction would have happened already. When you place a market buy (resp. sell), you are saying that you will accept the offer (resp. bid) that's currently outstanding. But by the time your trade gets to the top of the queue, those numbers might have changed. This is particularly true of thinly traded stocks and after-hours trades. But even during normal hours it can happen. Suppose you put in a market buy order for 100 shares, and there's someone else (the lowest offerer) offers 10 shares at $238. So you buy 10 shares at $238. But the next lowest offerer had his sell order at a limit of $245! Oops, you will instantly buy as many (up to 90 shares) of his as you can... at $245.
There are people who place ridiculously out-of-the-money limit orders after hours, or on thinly traded stocks, in the hopes that some chump will come along and place a market order that will get filled at the ridiculous price. This is why market orders are not allowed out-of-hours. But there are still occasionally people who will decide that they really want the shares NOW, and will buy them anyway.
I have no idea what happened in this case, but that is my explanation... and I almost never place market orders any more.