Spain's largest bank joins the growing list of traditional financial institutions quietly building Bitcoin exposure through regulated channelsBanco Santander, the eurozone’s largest bank by market capitalization, has reported owning approximately $4.3 million in US spot Bitcoin ETFs. The $4.3 million position shows up in Santander’s regulatory filings as exposure to US-listed spot Bitcoin ETFs. The bank scored around 35% on the 2026 Bitcoin Bank Adoption Index, placing it in what researchers categorize as the middle tier. AdvertisementThe broader Santander crypto strategyThe ETF disclosure fits into a pattern of deliberate, measured crypto integration at Santander. This mirrors what several major US banks have done after the SEC approved spot Bitcoin ETFs in January 2024.