Could be…
You can check out Monzo’s user growth curve & the number of users signing up per day here. The latter figure has been jumping recently but my guess is that, that’s thanks to Martin Lewis’ promotion.
Unfortunately it seems hard to distinguish between the compound effect of Monzo having more users - & their effect on word of mouth referrals - & seasonality, to me. It’s less clear what’s driving Revolut’s growth though.