Do large intraday reversals always signal a continuation in the latter direction in the short term/long term?
–I don’t have any statistics related to your question, but I know that many intraday reversals are only intraday traders inventory adjustments. –Many such intraday reversals are inventory adjustment as as Michele replied or trapped traders squaring off. Not all intraday reversals fall into this category. Watch the price action next day, if it revisits the prior day reversal levels, then it is likely to be inventory adjustment.
–Any Trend Reversal will begin with an Intraday Reversal but all Intraday Reversals will not be Trend Reversals. I dont have the Statistics but can tell you the probability will be very low. But if you are aware of Crucial Levels and you see a Reversal at those levels you can catch the down Move Early.