<p style="text-align:start;" size="0" _root="undefined" __ownerid="undefined" __hash="undefined" __altered="false">Shares of Marqeta debuted Wednesday on the Nasdaq, hitting $31 by the afternoon—which gives the company a $16.6 billion market cap and founder and CEO Jason Gardner a $1.6 billion net worth, by <em>Forbes’</em> reckoning.</p>