To break the longterm uptrend, FBU would need to close below the $11.15 low of 17/8/07.

Sell signals would also be generated by price action dropping below the trendline, moving average or either of the trailing stops.

The indicators shown at the top of the chart will give Sell signals when they break below their green "signal" lines, apart from the DMI where you are looking for the green line (+DI) to cross below the red line (-DI).

A fall in the On Balance Volume would be bearish, especially if it was a steep drop (ie the price fell on very heavy volume).