If your startup is evaluating high-yield treasury accounts, you’ve probably come across Brex, Mercury, and Rho. Each promises government-backed safety and stronger returns than traditional bank accounts, but the details matter: fees, liquidity, automation, and minimums can significantly impact your runway. Brex and Mercury both position treasury as part of their broader banking platforms. Rho also offers treasury as part of its all-in-one finance suite, but differentiates with automation tools and accounting integrations that can help startups streamline cash management.
This blog post offers a definitive guide to help you compare Brex, Mercury, and Rho treasury accounts, so you can decide which option best fits your startup.
Key takeaways
- Rho is the only platform of the three that allows startups to directly own U.S. Treasury Bills in their company’s name, offering the highest level of security and transparency for corporate cash management. It provides competitive yields up to 4.25% and powerful automation for startups that meet its $350K minimum.
- Brex offers the highest advertised yield (up to 4.35%) with no minimums by investing your cash in a government money market fund. It prioritizes speed with same-hour liquidity, making it an accessible option for any-stage startup.
- Mercury uses managed money market and bond funds from J.P. Morgan and Morgan Stanley to offer yields up to 4.23%. It is designed for later-stage startups that meet its $250K minimum.
What is Rho Treasury?
Rho Treasury is part of Rho’s all-in-one business banking and finance platform, which also includes cards, bill pay, and checking. Treasury is designed to help startups maximize returns on idle cash while reducing manual work through automation and integrations.
What does Rho Treasury offer?
Rho Treasury provides yields up to 4.25% net of fees, with a $350K minimum balance requirement. Unlike Brex or Mercury, Rho gives startups the option of allocating between U.S. Treasury Bills (for fixed NAV and government-backed stability) or the Morgan Stanley MULSX fund (for a diversified, short-term mutual fund approach).
A unique differentiator is that Rho’s team helps you choose the right mix of your portfolio, set up auto-movements, and start earning without figuring it out alone. Liquidity typically takes 1–3 business days, but rule-based automation ensures operating accounts are always topped up when needed.
Key features include:
- Up to 4.25% yield net of fees, depending on balance tier.
- Choice of investments: U.S. Treasury Bills or Morgan Stanley MULSX fund.
- Guided setup support to balance Treasury, Savings, and Operating.
- Rule-based automation to sweep funds between checking and treasury.
- Direct accounting integrations with QuickBooks, NetSuite, and more.
- Custodied at Apex Clearing with SIPC protection (up to $500K, $250K for cash).
Who is Rho Treasury best for? Rho Treasury is best for startups that prioritize capital preservation and security above all else. Its unique model of allowing direct ownership of U.S. T-bills is designed for well-funded companies seeking to minimize risk. The platform's sophisticated automation complements this security-first approach, creating an efficient, hands-off system for strategic cash management.
What is Brex Treasury?
Brex Treasury is part of Brex’s all-in-one business banking platform. It allows startups to earn on idle cash while using Brex’s broader suite of products such as cards, bill pay, and FDIC vault services. Treasury is positioned as an additional feature rather than the primary focus of the platform.
What does Brex Treasury offer?
Brex Treasury provides yields up to 4.35%, with no minimum deposit requirement and same-hour liquidity. Funds are invested in the Dreyfus Government Cash Management Fund (DGVXX), a government money market fund designed to minimize risk and preserve capital.
Key features include:
- Up to 4.35% yield, depending on balance tier.
- No minimum deposit required.
- Same-hour liquidity for fast access to cash.
- Integrated with Brex banking, cards, and SIPC protection (Treasury) / FDIC up to $6M (Vault).
- No advisory or management fees.
Who is Brex Treasury best for? Brex Treasury is the ideal choice for startups that prioritize speed and accessibility over all else. With no minimum deposit and same-hour liquidity, it’s a perfect fit for early-stage companies needing immediate access to cash. While its automatic top-up feature is useful, it lacks the sophisticated, rules-based engine of a more specialized treasury platform like Rho.
What is Mercury Treasury?
Mercury Treasury is an investment product built into Mercury’s startup banking platform. It gives startups access to managed portfolios powered by J.P. Morgan and Morgan Stanley, but requires a larger cash balance to qualify.
What does Mercury Treasury offer?
Mercury Treasury offers yields up to 4.23% net of fees, with portfolios split across J.P. Morgan’s Treasury Plus fund and Morgan Stanley’s Ultra-Short Income Portfolio. Withdrawals are same-day for the J.P. Morgan fund and 1–2 business days (up to 4) for the Morgan Stanley fund.
Key features include:
- Up to 4.23% net yield (after advisory fees of 0.15%–0.60% annually).
- $250K minimum balance required.
- Same-day or 1–2 business day liquidity depending on portfolio.
- Custodied at Apex Clearing with SIPC protection (up to $500K, $250K for cash).
Who is Mercury Treasury best for? Mercury Treasury is best suited for later-stage startups with $250K or more in idle cash who are specifically seeking portfolios managed by well-known institutional names like J.P. Morgan and Morgan Stanley. It occupies a middle ground on accessibility, offering a solid fund-based solution for companies that have outgrown Brex but may not yet require the direct ownership model and advanced automation offered by Rho.
Brex vs Mercury vs Rho Treasury comparison guide
All three fintech companies—Brex, Mercury, and Rho—offer treasury accounts that help startups earn more on idle cash while maintaining liquidity. While the core idea is the same, the differences in yield, fees, automation, and minimums are important when deciding which option is best for your business.
1) Yield & portfolio
- Rho: Up to 4.25% net yield after a 0.15%–0.60% management fee.
- Brex: Up to 4.35% total return with no management fee.
- Mercury: Up to 4.23% net yield after a 0.15%–0.60% management fee.
The crucial difference is the underlying portfolio structure. Brex and Mercury both invest your cash into shares of managed funds. In contrast, Rho is the only platform that gives startups the choice to directly own U.S. Treasury Bills, offering a superior level of security and transparency.
2) Liquidity & automation
Liquidity
- Rho: Standard 2–3 business day settlement for directly owned T-bills.
- Brex: Same-hour liquidity via a money market fund.
- Mercury: Same-day to multi-day depending on the managed fund.
Automation
- Rho: Sophisticated, rule-based automation to manage cash flow between accounts.
- Brex: Automatic top-ups into treasury.
- Mercury: Basic scheduled transfer rules.
3) Accessibility & fit
- Rho: $350K minimum; designed for well-funded, scaling startups.
- Brex: No minimum; accessible for early-stage companies.
- Mercury: $250K minimum; later-stage startups.
Rho vs. Brex vs. Mercury Treasury: At a Glance
| Feature | Rho Treasury | Brex Treasury | Mercury Treasury |
|---|---|---|---|
| Max yield | Up to 4.25% net (after 0.15–0.60% fees) | Up to 4.35% | Up to 4.23% net (after 0.15–0.60% fees) |
| Fees | Management fee 0.15–0.60% annually | No management fees | Management fee 0.15–0.60% annually |
| Investments | Choice of U.S. Treasury Bills or Morgan Stanley MULSX | Dreyfus Govt. Cash Management Fund (DGVXX) | J.P. Morgan Treasury Plus + Morgan Stanley Ultra-Short Income |
| Custody / Protection | Apex Clearing, SIPC protection ($500K, $250K cash) | SIPC (Treasury) / FDIC up to $6M (Vault) | Apex Clearing, SIPC protection ($500K, $250K cash) |
| Liquidity | 2–3 biz days (T-Bills), 1–2 biz days (MULSX) | Same-hour | Same-day (JPM), 1–2 biz days (MS; up to 4) |
| Automation | Rule-based automation + accounting integrations; guided setup | Automatic top-ups | Basic transfer rules |
| Minimums | $350K minimum | None | $250K minimum |
| Best for | Startups prioritizing security via direct T-bill ownership and automation | Startups seeking simple, no-fee, fast liquidity | Later-stage startups with large idle balances |
Wrap-up: Brex vs Mercury vs Rho Treasury
Are you considering a treasury account to put your startup’s idle cash to work? While all three platforms offer competitive yield, the underlying investment structure is a critical distinction for founders focused on capital preservation.
For startups prioritizing maximum security and transparency, Rho Treasury stands alone. As the only platform of the three offering direct ownership of U.S. Treasury Bills in your company’s name, it provides unparalleled peace of mind. Combined with powerful automation and integrated finance tools for those who meet the $350K minimum, Rho is the definitive choice for well-funded startups that view their treasury function as a core part of their long-term financial strategy.
For startups that don't meet Rho's minimums or require instant liquidity, Brex Treasury offers an accessible alternative. By investing your cash in a government money market fund, it provides a high yield with no minimum deposit and same-hour access. Its auto-top-up feature makes it a flexible tool for day-to-day cash management.
Mercury Treasury operates on a similar model, using managed funds from J.P. Morgan and Morgan Stanley for startups with over $250K in idle cash. It is a solid option for later-stage companies that are comfortable with the fund structure and its fee schedule.
Ultimately, while Brex and Mercury provide excellent yield-generating tools, Rho offers a true corporate treasury solution. The choice depends on your priority: maximizing yield and speed with funds, or maximizing security with direct ownership.