Oil prices have been climbing for the last four weeks, though the climb has been hesitant, uneven, and has failed to convince traders of a stable trend. But with the bullish signs for oil multiplying, traders are starting to grab the opportunity, despite some hesitancy. Bloomberg reported this week that speculators had been expanding their long positions on crude, with the net number reaching almost 196,000 lots this week, on expectations of stronger demand for crude during the second half of the year. Indeed, the first half has largely…