Secure Digital Markets (SDM), an institutional trading and lending desk, said it sent a $1 million payment to Kraken over the Lightning Network on Jan. 28.
SDM described the transfer as the largest publicly reported Lightning transaction to date and framed it as a proof-of-concept for seven-figure payments between regulated counterparties.
How the payment was routed
SDM said the payment cleared in 0.43 seconds.
It was routed via Voltage’s managed Lightning infrastructure, which offers node management, pre-provisioned liquidity, and uptime guarantees aimed at exchanges and trading desks.
Voltage CEO Graham Krizek said the transaction marked an important milestone for institutional bitcoin payments:
“[It highlights] its ability to meet enterprise requirements.”
Prior “record” was about $140,000
The previously publicized single-payment milestone was about 1.24 BTC, roughly $140,000 at the time.
SDM’s transfer, by contrast, was a clean seven-figure payment in one transaction.
Lightning capacity has rebounded
Lightning metrics remain relatively small compared with bitcoin’s overall market value, with most documented usage skewing toward smaller payments.
Public Lightning channel capacity fell from over 5,400 BTC in late 2023 to about 4,200 BTC by mid-2025, before rebounding to a new all-time high of over 5,600 BTC by December.
Bitfinex previously capped Lightning deposits at 0.04 BTC, before raising limits to 0.5 BTC per payment and 2 BTC per channel.
Fidelity Digital Assets and Blockstream have also pointed to institutional potential, citing capacity growth since 2020 and ongoing Lightning software improvements aimed at lower latency and better service-provider support.
