Bid tone around Sterling weakened somewhat in Asia, pushing the GBP/USD pair into the red; however, losses are being capped around 1.4636 (38.2% Fibo of 1.5930-1.3835).Hovers around 1.4650Cable currently trades around 1.4650; down 0.27% on the day. The spot clocked a high of 1.4718 in the NY session before clocking a low of 1.4627 levels in Asia.Latest Brexit polls once again showed ‘remain’ camp is still the overall winner. However, that failed to push the spot above the NY session high of 1.4718. The UK data docket is thin with just public sector borrowing figures due for release. The volatility is likely to stay high and trading volumes thin ahead of Thursday’s referendum.Apart from Brexit related news flow, markets would also take note of Yellen’s comments at her testimony, which begins later today.GBP/USD Technical LevelsA breakdown of immediate support at 1.4636 (38.2% Fibo of 1.5930-1.3835) would expose psychological support at 1.46. A violation there would open doors for a drop to 1.4549 (23.6% Fibo of 1.3835-1.4770). On the other side, acceptance above 1.4718 (NY session high) could yield re-test of latest cyclical high of 1.4770, above which 1.48 (zero figure) stands exposed.