Robinhood said today it has spent two years building its own trade clearing system from the ground up, and says it is the first such system built in the industry in the last decade.

The move comes alongside the lowering of certain fees, such as bank reversals ($30 down to $9), and will certainly bring higher profits due to lower costs. Menlo Park, Calif.-based Robinhood previously used a company called Apex Clearing for its trade clearing.

Robinhood, known for its fee-free trading and millennial user base, now claims 6 million customers. From CNBC:

About seventy Robinhood employees based in Lake Mary, Florida, quietly built the “Clearing By Robinhood” technology from scratch, and worked on getting necessary regulatory approval. To do so, the company formed a new entity called Robinhood Securities in 2016 and received regulatory approvals from FINRA, DTCC and OCC.

The move will give Robinhood more visibility into its customer journeys, the company says. Robinhood has been at the forefront of investing disruption in its brief existence — look no further than JPMorgan Chase’s copycat fee-free offering, You Invest, to see how it is influencing traditional players.

A recent Seeking Alpha post called out Robinhood for the amount of money it makes from high-frequency traders. Many brokers refuse to sell their order flow to HFT firms, the piece’s author argues, but Robinhood not only sells the order flow, but makes 10x the typical fee from doing so. This amounts to selling out its millennial customers, following the adage, “If you’re getting it for free, you are the product.”

Robinhood earns interest on money it holds, its dealflow, and lends money for margin trading to Robinhood Gold account holders. The Motley Fool explored how Robinhood makes money back in March. Bank Innovation touched on this subject earlier this year as well. Robinhood has raised $539 million at a $5.6 billion valuation and is reported to be considering an IPO.