Been trading for a while now and realized a lot of newer people don't really understand what GTC orders are, so figured I'd break it down since it's actually pretty useful once you get the mechanics right.

So basically, a Good 'Til Cancelled order - that's what GTC stands for - is just a buy or sell order you place at a specific price that stays active until either the price hits and your order executes, or you manually cancel it yourself. Unlike day orders that just disappear at market close if they don't fill, a GTC order can sit there across multiple trading sessions. That's the whole appeal really. You set your target price and the order just hangs there waiting.

The main benefit is you don't have to babysit the market every single day. Say you think a stock trading at 55 bucks is overpriced but would be a solid buy at 50. You just drop a GTC buy order at 50 and go about your day. If it hits that level, boom, your order fills automatically. Same thing works for selling - maybe you're holding something at 80 and want to lock in profits at 90. Set a GTC sell order and let it work for you.

Now here's the thing though - brokerages won't let these just sit forever. Most will auto-cancel your GTC order after 30 to 90 days depending on the platform. So you can't just set it and completely forget about it.

There are some legit risks you should know about though. Market gaps are a big one. Picture this: stock closes at 60, then overnight some news drops and it opens at 50 the next morning. If you had a GTC sell order at 58, it might execute way lower than you expected. That gap can catch you off guard. Same with random price spikes from volatility - a stock might dip briefly and trigger your buy order right before it crashes further. You lose the chance to buy even lower.

Another thing is people just forget they have open orders. Market conditions change, your strategy evolves, but that old GTC order is still sitting there waiting to execute. That's why periodically reviewing your open orders is actually important.

Compared to day orders which expire at market close, GTC orders are way different in scope. Day orders are for people trying to catch quick moves within a single session. GTC orders are for people willing to wait days or weeks for a specific price target. It's really about your timeframe and strategy.

Bottom line: GTC orders are solid for automating your entries and exits at predetermined prices without constant monitoring. Just remember they come with risks like market gaps and unintended fills from volatility. Keep an eye on your open orders and adjust them as your market view changes. That's the smart way to use them.