Japanese spot Bitcoin ETF market could grow to around $18.4 billion by fiscal 2028 under a bullish adoption scenario. Don't Miss:An $18.4 billion Bitcoin ETF market would account for only about 0.13% of that, suggesting that even a relatively small shift in household portfolios could create a sizable market. It would also represent around 1% of Japan's public equity investment fund market, which exceeds $1.8 trillion. The estimate assumes three primary sources of investment demand. Japanese investors could gain Bitcoin exposure without directly managing wallets, seed phrases, or crypto exchange accounts.