September 6th, 2012, 12:53 pm
QuoteOriginally posted by: farmerTell me if this is what you are saying. If a stock goes up 1% with only 10 consecutive ticks at the offer, then a news search will almost surely show some news for that ticker symbol, or some general market-moving news. But if the same stock goes up 1% after ticking at the offer 98 out of 100 ticks, probably not, probably just a big buyer.Not necessarilly. It is all about what happens to the trade prices in a sequence of buys and sells. For the first case, it depends on how the trade price changed in between the trades (ticks). If you have, lets say for a day, 10 trades at the offer (all buys) and each of them moved the trade price by 1%, then for this day the models says that there is news 100% of the time. pnew=1 - 0/10For the second example, if you have 98 consecutive buys and 2 consecutive sells, and the trade price has changed for 50 of the consecutive (same sign) 99 trades, then the probability of having news in this particular day is:pnews=1- 50/99 = 49%