Save yourself the risk of loss and exponentially raise your chances of winning since these events are few and far between...get bloomberg.
They highlight (red)/asterisk the m&a, upgrades, FDA approvals/failures, DOJ investigations and they provide you the ticker so you don't have to look it up if you don't have it memorized.
if you really want to never lose and consistently make the big bucks (100K-+$1M) in a few seconds, then you need bloomberg.
Also, you have about 3-5 seconds to deploy all your capital towards the trade so you def need a fast ems and smart router. No time to put in the limit, your price should be current inside + like 10 cents for small news or +50 cents for m&a or a fraud/doj investigation. For shares, configure a few shortcut buttons (long and short) to whatever your $ limit is but since you are using a limit on your order, as long as you are within that 3second time frame you can order up to 50K shares per order, no guarantee you will get filled since mkt will def move up/down so you may have to order several times, each time you raise the limit by your addition/subtraction to the inside--so 1st order will be inside + .10, second will be new inside +/- 10, etc.
Initial order should be within 3-4 seconds of news, last order no later than 6seconds. You have about 2-3 seconds to buy/short as much shares as you can. Anything later could cause a huge loss, so the trade should be avoided. You unload about 5% of your position per order, usually 20-45 seconds after you open the position.
Also, since you can't control when news happens--it could happen at 8am or 4:15pm (outside mkt hours) you have to be ready and alert at all times.
Risk of loss for the above is less than 1%. If you do lose, it's either you reacted too late or someone beat you to the chase.
HFT/Algo strategies always lose on the initial pop (or drop), however, they make up for the relatively small loss over the next minute when everyone else jumps aboard and the volatility in the name picks up.
Good luck, it takes months of practice but consistency will get you to 8 figure incomes a year with just $1-2Mill in capital.