Well..... good sign of a trend would be when a certain economic condition causes a rally and a reversal of that condition also causes a rally (or at least doesn't result in a drop).
EXAMPLE:
Plummetting oil prices ease inflation concerns causing this latest rally.
Then, today OPEC announces the first official cut in output in quite a while, and the price of oil immediately rebounds. But the market doesn't drop. Why... because energy was going to be the only component posting losses for the quarter, and now they will likely post gains along with everyone else.
IOW, bad news is good, and good news is great.