Needless to say, trading into a volatile market is a high risk game in terms of giving up some of your shares on a trade in hopes of buying the shares back at a cheaper price (so-called 'scalping'). I would not put in a gtc order in advance of even seeing the actual news. If your timing and positioning is not just right you risk selling shares for cheap and seeing the price continue to rise so that it's hard to buy back the shares. Any trading play like this involves 2 decisions, when to sell and when to buy back. In theory you can make a good spread, but putting it into practice to make some cash without giving up on your best opportunity is very difficult.
The price action is almost impossible to predict. It depends among other things on just what the TLD is. About the only thing to go by is your gut feeling on how the stock runs vs how good and clear the tld data is. One possible indicator is just how high the stock runs on an absolute basis. BTW in general the stock action will probably be much different if there is a partnership deal announced than if nothing but tld alone comes out. Other than a gut feeling that x TLD should be worth y$ or z$ vs the actual trading in real-time after TLD is announced, the only strong indicator is volume. Topping action will probably be accompanied by falling off in volume.
It's just about certain that at some point(s) the stock will become over-bought and subject to pulling back. But amid heavy trading and large moves, it's hard to impossible to differentiate a temporary pull-back from a more solid pullback. If one wants to try to play a trading game one should, first of all, be very aware of the brokerage rules on trading, e.g. if non-margin then you might have to wait 3 days for settlement to buy back anything you sell while in a fully margined situation you can probably sell and buy back once even within the same day as you sell. But it's best to make quite sure beforehand what rules your broker will enforce so you don't get surprised if e.g. you intend to trade intraday but your broker won't let you buy back until after the sale settles (ie after 3 days).
Anyway, in volatile trading some temporary pullbacks are bound to happen but it's super hard to tell a very short term pullback from a longer-term pullback when you are watching in real-time. You might get some sense of possible patterns by looking at how cpxx traded or other similar cases where the tld was a very big surprise. Also, unless you are very sure you know what you are doing, you'd probably be well advised to limit your trading forays to small chunks of your total holdings, if you want to try to be sure not to just end up losing some number of shares to selling too early in the middle of a history-making runup (or not - the pattern might end up being a huge rise followed by a large pullback and then price stagnation at a level well off the volatility driven top).
Again, there may be a huge trading opportunity but there is also a chance of selling into a small pullback and then seeing the stock run a lot further up after you have sold into the early-on rise. All knock on wood that we should be so lucky as to see things move the way we want it to and have that be well-justified repricing of the stock and not just an unsustainable buying frenzy.
