Extend your runway without cutting headcount
Two extra points of yield on eighteen months of runway buys weeks of extra time. Here is the arithmetic.
Not FDIC insured · Withdrawals within 48 hours · KYB required · Rates as of September 2026
The short version
- A round is spent over eighteen months, so most of it is a reserve for most of that time. Across the period the balance averages half the opening amount.
- Two extra points of yield on an eighteen-month runway buys about eight days of runway — less than the number usually quoted, and the size of the round does not change it.
- Only the third layer of cash qualifies. Operating and buffer stay at the bank, and they are what makes the reserve deployable.
- Withdrawals take up to 48 hours. On a locked tier an early exit returns capital and forfeits accrued interest, with no penalty on principal.
- Not FDIC insured. Eligible funds are covered through OpenCover for named protocol events, up to 100% of USD value, subject to policy terms, limits and exclusions.
What idle cash costs you after a raise.
A round is not spent on the day it closes. It is spent over eighteen months, which means most of it is a reserve for most of that time — sitting at whatever rate nobody chose.
The whole round lands in one account
The wire arrives in the operating account — the account least likely to pay anything. In the weeks that follow, nobody owns the job of moving the portion that will not be spent, because everybody is hiring.
Most of it will not move for a year
On eighteen months of runway and a steady burn, roughly a third of the round is still on the balance sheet at month twelve. That portion is a reserve whether or not anyone in the company calls it one.
The rate you earn is the one nobody negotiated
Whatever the bank applies by default becomes the treasury policy. Tiered balances, promotional windows and relationship conditions all sit between the advertised number and the rate on your statement.
Foregone yield is runway, restated
Interest not earned and cash spent are the same line in the model. The question is not whether the reserve should earn something — it is how much of the balance can safely sit two business days away from you.
How much is actually sitting there
Take a round spent evenly over eighteen months. A third of it is still on the balance sheet at month twelve, and across the whole period the balance averages half the opening amount. That average is the number the yield decision is made on — not the headline round size.
| Round raised | Still held at month 12 | Average balance over 18 months |
|---|---|---|
| $3,000,000 | $1,000,000 | $1,500,000 |
| $6,000,000 | $2,000,000 | $3,000,000 |
| $10,000,000 | $3,333,000 | $5,000,000 |
Straight-line burn, no revenue, no follow-on. Real burn curves step up as you hire, which pulls the average down. Use your own balance history rather than this table.
Two points of yield, in weeks of runway.
Below is the full calculation for one company shape, so you can check it against your own model. It is an illustration, not a promise — and the honest answer is smaller than the one usually quoted.
The company in this example
- 01
Start from the average balance, not the opening balance
You spend the money as you go. With a straight-line burn, the balance across the eighteen months averages half the opening balance: $2,250,000, not $4,500,000.
- 02
Apply the spread over the period
$2,250,000 × 2.00 points × 1.5 years = $67,500 of additional interest, before tax and before compounding.
- 03
Divide by the monthly burn
$67,500 ÷ $250,000 per month = 0.27 months of additional runway.
- 04
Convert to the unit the board uses
0.27 months is about eight days — a little over one week. That is the honest answer for this shape, and it is smaller than the number most decks quote.
The size of the round cancels out.
Spread as a decimal, runway in years, deployed share as a decimal. Run the eighteen-month case through it — 26 × 0.02 × 1.5² × 1 — and you get 1.17 weeks, the same eight days as the long version above. Two companies with the same runway and the same spread gain the same number of weeks whether they raised $3M or $30M. What moves the answer is the length of the runway, because it enters squared, and the share of the balance you are willing to place two business days away.
Weeks gained, by runway length
| Runway at the start | 2.00 points — no-lock tier at 6.00% | 2.75 points — 12-month tier at 6.75% |
|---|---|---|
| 12 months | 0.5 weeks (4 days) | 0.7 weeks (5 days) |
| 18 months | 1.2 weeks (8 days) | 1.6 weeks (11 days) |
| 24 months | 2.1 weeks (15 days) | 2.9 weeks (20 days) |
| 30 months | 3.3 weeks (23 days) | 4.5 weeks (31 days) |
| 36 months | 4.7 weeks (33 days) | 6.4 weeks (45 days) |
Illustration only. Straight-line burn, the entire balance deployed, simple interest, before tax, against a hypothetical 4% baseline. Coinstancy Pro rates as of September 2026 and not guaranteed.
- It assumes the entire balance is deployed. It will not be — multiply the result by the share that actually sits in the product. At 60% deployed, the eighteen-month, two-point case is about five days, not eight.
- The two points are an illustration against a hypothetical 4% baseline, not a quoted or sourced bank rate. Use the effective rate from your own statement instead.
- Simple interest, before tax, no compounding. Neither the baseline nor the 6.00% tier is a guaranteed rate.
- The 2.75-point column requires the twelve-month lock. Exit that tier early and capital is returned while accrued interest is forfeited — the weeks gained go back to zero.
- Withdrawals take up to 48 hours. This arithmetic only applies to money that can wait two business days.
- The version you will see elsewhere applies the full rate to the full opening balance for the full period. That double-counts money you have already spent, and it doubles the answer.
Operating, buffer, reserve.
The allocation decision is not "should we move the cash". It is "which layer of the cash", and the answer is only ever the third one.
Operating
Payroll, accounts payable, taxes and card spend already committed. This layer is never a candidate for anything that settles in 48 hours, at any rate.
Buffer
The layer that absorbs a surprise — a delayed collection, an unplanned hire, a bridge to the next tranche. It is also what makes the reserve deployable: the buffer covers the 48-hour window so the reserve never has to be reached in a hurry.
Reserve
What is left once the first two layers are funded, and that you can name today as not needed for three months or more. This is the only layer this product is designed for.
Applied to the $4,500,000 and $250,000 monthly burn from the previous section. The split is a worked example, not a recommendation — the buffer in particular should come from your own worst month, not ours.
| Layer | Sized on | Amount | Where it sits |
|---|---|---|---|
| Operating | 2 months of burn | $500,000 | Bank checking |
| Buffer | 3 months plus contingency | $1,000,000 | Bank savings or money market fund |
| Reserve | Remainder | $3,000,000 | Candidate for allocation |
Two thirds of the balance ends up as reserve here. Feed that back into the formula — 26 × 0.02 × 1.5² × 0.67 — and the eighteen-month case gives about 0.8 weeks rather than 1.2. Segmentation costs weeks, and it is still the right order of operations.
A reserve does not have to go into one tier. Splitting it across terms keeps a slice coming free every quarter, which matters more to a company that may raise, hire or pivot inside the period.
- The tiers are 3, 6, 9 and 12 months, so a reserve can be split rather than locked in one block
- Splitting the reserve across tiers means a slice comes free every quarter without an early exit
- The no-lock tier at 6.00% can hold the portion you are least certain about
- The 7.00% introductory rate applies to the first six months and is not a permanent tier
- Early exit on any locked tier returns capital and forfeits accrued interest — no penalty on principal
What investors think of this allocation.
We cannot speak for your investors, and we are not going to put words in their mouths. What we can do is list the questions this allocation reliably raises, and what a defensible answer looks like on each.
| The question | What you should be able to say |
|---|---|
| Is this insured? | No, not in the sense the question means. There is no FDIC insurance. Eligible funds are covered through OpenCover for specific protocol events — code bugs, oracle manipulation or failure, liquidation failure, malicious governance takeover — up to 100% of USD value and subject to policy terms, limits and exclusions. |
| What happens if we need the money? | Withdrawals are available within 48 hours. On a locked tier, an early exit returns the capital and forfeits the accrued interest, with no penalty on the principal. This is exactly why the operating and buffer layers stay at the bank. |
| Where does the yield come from? | Lending and liquidity provision on selected protocols — Curve, Pendle, Balancer, Beefy, Aave and StakeDAO — not a promotional subsidy. That is also why it is not guaranteed and carries risks a bank deposit does not. |
| Who holds the funds? | The protocols are non-custodial and you hold no keys. Coinstancy manages the allocation and the monitoring; you interact with the dashboard. |
| Is this a crypto bet? | Eligible assets are USD or USDC only. The exposure is smart contract risk and stablecoin risk, not price risk on a volatile asset. Depeg of the underlying stablecoin is explicitly not covered. |
| How large is the allocation? | That is the number to bring already decided: the reserve slice as a percentage of total cash, with a floor under the operating and buffer layers, a named approver and a review cadence. |
The allocation is easier to approve when it arrives as a policy with limits than as a yield number. Six lines are usually enough.
- Eligible instruments, named — and the ones explicitly excluded
- A hard floor in months of burn that must remain at the bank
- A maximum share of total cash allocated outside insured deposits
- Who approves a deposit, and who approves a withdrawal
- A review cadence, and the conditions that trigger an unwind
- How the position is described in board reporting and in the audit file
Any one of these on its own is a sufficient reason to leave the cash where it is.
- Your investor agreements or side letters restrict where corporate cash may be held
- Your treasury policy bars any smart contract exposure, and nobody wants to reopen it
- Runway is under twelve months, where the weeks gained are days and the attention is better spent elsewhere
- You are mid-raise and the balance may move on short notice
- No one on the team can own the position, the reporting and the review
- The absence of FDIC insurance is a hard line for your board, which is a legitimate position
The full coverage scope, with covered events and exclusions, is on the coverage and risk page. How protocols are chosen and reviewed is on the protocols page.
The runway calculator.
Everything above is one company shape. Yours has a different burn curve, a different revenue line and a different bank rate, and all three change the answer.
Burn rate and runway calculator
Enter cash on hand, monthly revenue and monthly expenses. It returns net burn, months of runway, and what the idle portion would have earned over the same period.
Or do it on the back of an envelope
Two lines, and you can check the calculator against them. Keep the runway in years in the second one, because it enters squared.
Use the effective rate from your last statement as the baseline for the spread, not a headline rate from a comparison page — including ours.
Both calculators are illustrations built on the inputs you provide. They are not projections, not advice, and no rate they display is guaranteed.
Setup in one week.
Five days of work on your side, in order. The clean case closes inside a week; the file that needs a clarification round does not, and we would rather say so here than after you have started.
Size the three layers
Day 1Pull twelve months of balance history. Set the operating floor from committed spend, set the buffer from your worst month plus a contingency. What is left is the reserve, and it is the only figure the rest of the week depends on.
Write the one-page policy
Day 2Eligible instruments, the floor that stays at the bank, the maximum share allocated, the approver and the review cadence. Circulate it to whoever signs before anything else moves.
Gather the KYB file
Day 3Company registration documents, beneficial ownership information and identification for signatories. The funding account must be in the name of the contracting entity. Most of the elapsed time in onboarding sits on this step, not with us.
Submit and review the terms
Day 4Submit the file, then read the agreement and the coverage terms with the person who signs. Coverage scope, exclusions and limits are worth an hour before the first deposit rather than after it.
Choose the tier, then fund
Day 5Pick a single tier or split the reserve across the 3, 6, 9 and 12-month tiers. Fund in USD from the verified corporate account, or in USDC from an existing balance, once KYB has cleared.
What pushes it past a week
One week is the schedule for a company whose corporate documents are already in one folder. Everything below adds days, and none of it is unusual.
Request access, or ask the hard questions first.
Open an account directly. If your finance team needs the coverage terms and the KYB requirements before that, a call is the faster route.