I am still favoring BULLS

I am still favoring bulls hence

Technical : Pair is on it's way for a correction. Pair has not provided sufficient/significant clues of trend reversal. If you look at the monthly and weekly structure are making higher highs. 138.80-90 zone is highly a confluence zone where price may respect and halt the correction. If the sellers able to break the 138.80 zone then the bears will keep there first step for a bear run.

Fundamentals :
The JPY showed some strength despite Monday's downbeat Japanese GDP report, which showed that the world’s third-largest economy shrunk by the most on record during the second quarter of 2020. In fact, GDP contracted for the third straight quarter and plunged at an annualized rate of 27.8%, offering a bleak fundamental backdrop. (by a news feed.)
There isn't any major market-moving economic data due for release on Monday. This makes it prudent to wait for some strong follow-through selling before confirming that the GBP/JPY cross might have topped out in the near-term and positioning for any further near-term depreciating move.