Three banks are now live with realtime peer-to-peer payments on the ClearXchange network: U.S. Bank, Bank of America, and as of yesterday, JPMorgan Chase. U.S. Bank and Bank of America joined the realtime network in March.

P2P payments were realtime within Chase since 2012, but now they are realtime among all banks on the ClearXChange network.

Venmo and Square Cash may get all the attention, but bank peer-to-peer payments see more volume and larger payments. Chase QuickPay, the bank’s P2P solution, became part of the ClearXChange network in 2012. Usage is projected to grow 40% year over year, and Chase customers transferred $20 billion peer-to-peer in 2015, while the average transaction size is now more than $300, according to Chase.

Compare those numbers to Venmo, which processed $3.2 billion last quarter. Venmo grew 150% over 1Q 2015, according to CEO Dan Schulman on PayPal’s April earnings call. Ron Shevlin, research director at Cornerstone Advisors, puts the average Venmo transaction size at around $2, which seems low compared to the Chase number. Two possibilities: 1) People use Venmo much differently than they use bank-based P2P; or 2) People are not self-reporting accurately about Venmo usage, and they transact less frequently than they think they do.

ClearXChange was founded in 2011 and bought by the security consortium Early Warning Services in Oct. 2015. Early Warning was an advocate of realtime transactions as far back as 2013. Back in 2014, half of the country’s mobile banking users were on ClearXchange, but, as JPMorgan Chase CEO Jamie Dimon said in December, that number is about 60% now.

Some member banks, such as Capital One and Wells Fargo, are not yet live with ClearXChange’s realtime service. Wells Fargo has announced it will enable the sending of realtime payments for its customers in July. Wells customers can already receive realtime payments through the network, it was announced at the bank’s recent investor day.

Mike Kennedy, the founder and CEO of ClearXChange, said in 2014 that customers would be willing to pay for realtime, but so far only U.S. Bank is charging for the service. Bank of America and Chase are not.

Later this month, Chase will update the QuickPay area of its mobile app, which is where 75% of the bank’s P2P payments originate, the bank told us. The updated app will allow for faster payments via a streamlines user experience, mobile onboarding of P2P customers, access to phone contact lists, and greater control over QuickPay settings in the main settings area of the app.

Dimon mentioned plans to launch realtime P2P payments in his 2015 letter to shareholders, noting that the service would benefit Chase Pay, the bank’s mobile payments platform. The P2P service will remain free, he said. Apparently, it will after the soon-to-be-released update, too.

An open question in banking is how interoperable the various realtime systems will be. Other systems with realtime capability include Dwolla’s FiSync and Fiserv’s Popmoney.