Where to Park Cash Between RSU Vests: 5 High-Yield Accounts Compared
Cash from RSU vests shouldn't sit in checking earning near-zero. The best parking spots: a high-yield savings account (HYSA) — an online savings account paying a competitive, FDIC-insured rate — as the default; Treasury bills for cash earmarked for known future tax payments (their interest is exempt from state income tax); and your brokerage's money market sweep for zero-friction parking.
The practical system: one HYSA for vest cash, T-bills maturing just before each quarterly estimated-tax date, and a one-time check that your brokerage sweep isn't paying near-zero. Fifteen minutes of setup for hundreds to thousands a year on typical vest schedules.
Every vest, the same thing happens: shares land in your brokerage, you sell some (or they sell-to-cover), and a pile of cash sits there while you "figure out what to do with it." Weeks become months. That cash earns a fraction of a percent while inflation does its thing.
This isn't an investing question — it's a parking question. You need the money liquid, safe, and earning something while you decide its long-term home. Here are the five options worth knowing, with the tradeoffs that actually matter.
Important: every rate below is an illustrative example, not a current quote. Rates move constantly — the site owner must refresh these numbers against live rates before publishing or republishing this article.
The five options
1. High-yield savings account (HYSA)
An online savings account paying a competitive rate — e.g., 4.00% APY (illustrative). FDIC-insured, fully liquid, no market risk. The default answer for vest cash, and the right one for most people most of the time. Downsides: rates are variable (they fall when the Fed cuts), and transfers to your checking account take a day or two.
2. Money market fund
A mutual fund holding short-term government and corporate debt, bought inside your existing brokerage — e.g., 4.10% 7-day yield (illustrative). The advantage for RSU earners is friction: the cash is already at your brokerage, so there's no transfer at all. Check whether your brokerage's default cash sweep is already a money market fund — many are, and many people earning "nothing" are actually earning a competitive yield without knowing it. Not FDIC-insured (it's an investment, albeit an extremely conservative one).
3. Treasury bills
Short-term U.S. government debt you buy directly — e.g., 4.20% annualized on a 3-month bill (illustrative). Two genuine advantages: the interest is exempt from state income tax (meaningful in high-tax states), and the credit risk is as close to zero as exists. The tradeoff is liquidity mechanics: you pick a term (4, 8, 13, 17, 26, or 52 weeks), and selling early is possible but mildly annoying. Best for cash you know you won't touch for a few months — say, money earmarked for quarterly estimated taxes (see the RSU withholding fix).
4. No-penalty CD
A certificate of deposit you can withdraw from early without penalty — e.g., 4.05% APY (illustrative). It's the HYSA's slightly stricter cousin: usually a marginally better rate in exchange for marginally more hassle. Worth comparing when you open the HYSA anyway; not worth a separate quest.
5. Brokerage cash sweep (default)
Doing nothing — leaving vested cash in your brokerage's default sweep — e.g., 0.45% APY (illustrative; some brokerages pay far less). This is the baseline you're comparing everything against. Some brokerages default to a decent money market sweep; others default to nearly zero and hope you don't notice. Check yours. If it's the latter, options 1–4 are free money.
Side-by-side
| Account type | Illustrative yield* | Liquidity | Best for |
|---|---|---|---|
| High-yield savings | 4.00% APY | 1–2 day transfers | Default parking spot |
| Money market fund | 4.10% yield | Instant (in brokerage) | Zero-friction option |
| Treasury bills | 4.20% annualized | Term-based | Tax-aware parking in high-tax states |
| No-penalty CD | 4.05% APY | Withdraw anytime | Slight edge over HYSA |
| Brokerage sweep (default) | 0.45% APY | Instant | Baseline — verify yours |
*All yields are illustrative examples only, not current rates. Refresh before publishing.
A quick note on state taxes
One reason T-bills deserve a closer look: their interest is exempt from state income tax. In a high-tax state, that exemption can make a T-bill's after-tax yield beat a higher nominal HYSA rate.
Illustrative example — not tax advice, and all rates below are examples only. Say a T-bill yields 4.20% while an HYSA pays 4.40%, and your marginal state tax rate is 9%: the HYSA's after-tax yield is roughly 4.40% × (1 − 0.09) ≈ 4.00%, while the T-bill keeps its full 4.20%. The "lower" rate wins. Run your own numbers with live rates before choosing — the crossover point moves with both rates and your bracket.
The system I'd actually run
Keep it simple enough that you'll maintain it:
- One HYSA as the main vest-cash parking spot. Every vest, sweep the cash you aren't immediately investing into it. One account, one habit.
- T-bills for known-future tax payments. If you've set up the quarterly estimated tax habit, buy T-bills maturing just before each quarterly due date. State-tax-exempt interest on money that was going to the IRS anyway.
- Check your brokerage sweep once. If it's already a money market fund paying a competitive yield, you can skip step 1 for cash you plan to invest soon — the friction savings are real.
If you don't have a high-yield account yet, opening one takes about 15 minutes:
[AFFILIATE LINK: CIT Bank]
Disclosure: this is an affiliate link — if you open an account through it, EquityStack may earn a commission at no extra cost to you.
Pre-launch note: the link above is a placeholder until CIT Bank's affiliate program approves this site.
The bottom line
The difference between 0.45% and 4%+ on idle vest cash is hundreds to thousands of dollars a year for typical tech-comp vest schedules — for fifteen minutes of setup. This is the rare financial optimization that's pure upside: no risk, no lockup, no ongoing effort. Park the cash, then get back to deciding what it's for.