When trading on a longer timeframe, one will generally be using a wider Stop loss, counterbalanced by a more ambitious target. Major news announcements/stories often don’t change the overall trend direction, they just cause some short-term volatility, even a minor reversal, but this often corrects back in line with the overall, pre-news sentiment after a while. So with an intraday trade with a sub-100 pip Stop loss (for sake of argument!) this bounce can be enough to ruin the trade (it might hit the Stop, or delay the trade so much that it might run overnight, contrary to the strategy being used, or clutter your platform thus stopping other trades being taken, whatever), whereas with a longer-term trade, this volatility is to be expected and is generally simply absorbed within the natural Price movement expected within the trade.
Two examples of this - look at the charts for several Pairs, particularly Yen pairs, around the time of the mid-March earthquake: while this caused a large spike, the overall pattern of the pair is not that affected, in many cases. Take CHF/JPY as a good example of this, a Pair that often trends nicely. On the Daily chart, there is a sustained uptrend throughout that period. There is a major drop then rise on 16th/17th March, but two key points: 1) the drop fails to take out the Low of 09/02 (Feb for US readers!) (so would not hit sensibly-placed Stops) and 2) following the Spike, Price makes a higher high and the previous uptrend resumes. A well-planned, long-term trade on this pair would have survived this volatility, with the overall reason for being in the trade unaffected, while an intraday trade placed on the five minute, or the Hourly, or whatever, would most likely have been stopped out.
A second example is NFP, first Friday of every month (obviously!). Look at these on the five minute chart and there is often a very overextended bar (or cluster of bars), but quite often, once this has settled down, the previous overall move resumes. So again, an intraday trade would be likely to have been stopped out, while a longer-term trade has a higher chance of surviving.
Obviously there are exceptions to these examples, there have to be, as in trading nothing works every time (otherwise we would all be rich!), but this is a probability game at the end of the day, and the probability on this subject, in my opinion, is that placing an intraday trade immediately ahead of a major news event is overly-risky, whereas managing a longer-term trade through a number of events over time can work very well.
ST
