Banco Bilbao Vizcaya Argentaria SA has gone hostile in its pursuit of smaller Spanish rival Banco de Sabadell SA in a highly unusual move both for banking deals and the Spanish market. In truth, this looks like a face-saving admission of defeat more than a winning move.

BBVA is taking a big risk for a somewhat underwhelming reward: Going hostile means it won’t even get a proper look at its rival’s books before any deal, while the gain from success is a measly 3.5% addition to earnings per share when cost savings are achieved after three years by BBVA’s own estimates.