February 18, 2026 • 18 min read

The SPAC Investor's Guide: Trust, Valuation, and Arbitrage

SPACs are one of the most misunderstood instruments in public markets. When the structure is working as intended, they offer a rare combination of defined downside and asymmetric upside. When it isn't, they are a wealth transfer from public shareholders to sponsors.

The difference between those two outcomes usually comes down to one number: the cash in trust. This guide starts there — what the trust is and why it exists — then builds to how professional investors value SPACs against their trust and, finally, how arbitrageurs systematically exploit discounts between market price and trust value.

Part I: What is SPAC Cash in Trust?

When a Special Purpose Acquisition Company (SPAC) completes its IPO, the money raised from investors does not flow to the sponsor team. Instead, it is placed in a segregated trust account, typically invested in short-term US Treasury securities. This is the cash in trust — and it is the most important number a SPAC investor needs to know.

Why Does the Trust Exist?

The trust protects investors from fraud. In the early days of blank-check companies in the 1980s, sponsors sometimes raised money and then spent it on themselves without ever doing a deal. The trust structure — codified by the SEC in the late 1980s and adopted universally by modern SPACs — ensures that investor capital is protected until shareholders vote on an acquisition.

If the SPAC does not complete a deal within its deadline (typically 18 to 24 months), the trust is liquidated and shareholders receive their pro-rata share — approximately the original IPO price plus interest, minus trust expenses.

What Goes Into the Trust?

Most SPACs raise $10 per unit at IPO. The gross proceeds go directly into trust. The underwriter redeems its deferred commission at deal close (not from the trust in most structures), and the sponsor pays all operating expenses until an acquisition. So $10 in generally stays $10 in, growing daily with T-bill interest.

What Comes Out?

Two items reduce trust value over time: trust expenses (administrative and custodial fees, typically $50,000–$200,000 per year) and redemptions. When shareholders vote to redeem their shares, they receive the current trust balance per share and exit before the deal closes.

Cash in Trust Per Share

CIT per share is simple in concept:

In practice, the calculation is complicated by the lag between SEC filings (quarterly), daily interest accrual, and the difficulty of identifying which shares still have redemption rights after partial redemptions.

This is why PrimeRisk exists. We read the actual SEC filings, extract the trust balance and share count, and update the per-share figure daily with accrued interest — so you always have a current estimate without digging through 10-Q filings yourself.

Why This Number Matters

CIT per share is the downside floor for long SPAC investors. If you buy a SPAC at or below its trust value, your downside is limited to trust expenses and deal-close delays — not a permanent capital loss. This asymmetric risk profile is what attracts institutional arbitrageurs who build large SPAC books.

For retail investors, understanding CIT helps answer the question: "If this deal is terrible, what do I get back?" The answer is CIT per share — typically within a few cents of $10.

Part II: How to Value a SPAC

Valuing a SPAC is fundamentally different from valuing an operating company. Most traditional valuation metrics — P/E, EV/EBITDA, DCF — are irrelevant until a deal is announced. The right framework starts with one question: how does the market price compare to the cash in trust?

Step 1: Find the CIT Per Share

The starting point is the current trust value per share. You can find this in the most recent 10-Q filing under "investments held in trust account" or similar language. Divide by shares with redemption rights (public shares, not founder shares).

PrimeRisk automates this — we pull the figure directly from SEC filings and update it daily with accrued T-bill interest so you always have a current estimate.

Step 2: Calculate the Premium or Discount

A positive number means the stock trades above trust — the market is pricing in deal value. A negative number means a discount to trust — you can buy cheaper than the floor price.

What Drives the Premium?

Several factors push SPAC prices above trust:

• Deal quality: A high-profile target in a hot sector generates speculative buying.
• Sponsor reputation: Known sponsors with strong track records command a premium.
• Warrant optionality: If warrants are attractive, units trade up to reflect that.
• Market sentiment: In bull markets, SPAC premiums expand. In bear markets, they compress or go negative.

What Drives the Discount?

• Liquidity concerns: Low-volume SPACs trade below trust because investors fear they cannot exit before redemption.
• Deadline proximity: Near-expiry SPACs sometimes trade at tiny discounts as arbitrageurs price in timing risk.
• Trust erosion: High trust expenses or extended timelines can erode CIT below the original $10.
• Market sell-offs: Broad market selloffs can push SPAC prices below trust even on quality vehicles.

Step 3: Assess the Risk/Reward

With market price and CIT in hand, the framework is:

Other Factors to Check

• Extension history: How many times has the SPAC extended its deadline? Multiple extensions signal difficulty finding a deal.
• Redemption rate: High redemptions reduce the trust and the eventual deal size, which can be a signal of investor sentiment.
• PIPE availability: Modern deals often need a PIPE to close. No PIPE = deal risk.
• Sponsor stake dilution: Founder shares (typically 20% of post-deal equity) dilute public shareholders. Model the post-deal cap table.

Part III: SPAC Arbitrage 101

SPAC arbitrage is one of the most misunderstood strategies in markets — despite being practiced routinely by dozens of institutional funds. The core idea is deceptively simple: buy SPAC shares at or below their trust value, and redeem them for the trust value when the deal is put to a shareholder vote. The spread between your purchase price and the trust value is your near-risk-free return. You also get a Warrant as part of the transaction.

The Mechanics

Every SPAC shareholder with public shares has the right to redeem their shares for the pro-rata trust value, regardless of how they vote on the deal. This is a put option embedded in the structure.

The arb strategy exploits cases where the market prices SPAC shares below their trust value. You buy shares in the open market, hold them, and at the deal vote, redeem for cash from the trust. The gross return is the spread between your cost and the trust value.

Why Opportunities Exist

If this were obvious, the market would quickly eliminate the discount. Several structural factors keep opportunities alive:

• Liquidity constraints: Small SPACs with low float and wide bid-ask spreads are harder to arb at scale, so institutional funds skip them — leaving returns on the table for smaller players.
• Information asymmetry: Most investors don't know the exact trust value. Without that number, they can't identify the discount.
• Market stress: During broad selloffs, SPAC prices can trade significantly below trust as leveraged funds liquidate indiscriminately.

Risks

This is "near-risk-free," not "risk-free." The key risks:

• Trust erosion: Trust expenses and unusual withdrawals can reduce the redemption value below your purchase price.
• Extension delays: A SPAC can extend its deadline (usually requiring shareholder approval). Your capital is locked for longer.
• Liquidation shortfall: In rare cases of fraud or operational failure, the trust may not pay out in full.
• Opportunity cost: Capital is tied up for months. In a rising rate environment, even small discounts to trust may not compensate.
• Tax treatment: Redemption proceeds are typically treated as a return of capital, but consult your tax advisor.

Building a SPAC Arb Book

Institutional SPAC arb funds typically hold 20–60 positions, sized to manage concentration risk. The key metrics for position selection:

The Information Edge

The biggest challenge in SPAC arb is knowing the exact CIT per share at any moment. Filing dates lag by weeks. Daily accrual rates shift with T-bills. Expense charges are sporadic. Without accurate, current CIT data, you're flying blind.

This is the problem PrimeRisk solves. We extract trust values from every SEC filing, accrue interest daily at the current T-bill rate, and flag staleness — so you can screen for opportunities in seconds instead of hours.