am I the only one thinking IV levels of the big 4 banks at around 15% are 'cheap' at the moment?

True, HV45 is around that figure but over any lookback period that puts HV on a percentile rank of zero or close to it. On historical price behaviour it would be unusual if volatility levels remain this low for next 2/3/4 months and the chances of a return to V in the twenties must be higher than that of it dropping significantly further.

Furthermore, a few months ago , WBC had an IV of 21-25%, and WOW 13%.

Today, on figures for APRIL atm straddles, WBC is 15.25% and WOW 14%. Historically WBC has been way more volatile than WOW yet at the moment their IVs have converged. Spread trade long WBC options and short WOW options for a cash neutral trade?

I am long a couple of WBC straddles (delta neutral) at 15.25% IV, with the intention of gamma scalping while waiting/hoping for volatility to increase.

I would be interested in comments from the pros here on this line......