SPT reached $2 which fully diluted would mean $654 mil market cap, like-for-like this equates to Afterpay reaching $3.63 which didn't happen until 14 months after listing when it merged. Upon merger Afterpay had 230 million shares fully diluted so was worth $690 mil market cap at $3.
SPT at $1.60 is currently sitting around Afterpay's peak in its first year of $3.