A pro forma can be arithmetically perfect and still be fiction.
Every cell can tie out. The formulas can be clean. The returns can land inside the range the investor was hoping for. None of that tells you whether the deal is real. Internal consistency is not the same as realism. A model can agree with itself completely and still be detached from the market or current macro reality it is supposed to describe.
That is the gap where capital gets lost. Not in arithmetic errors, which are rare in a professional deck. In assumptions that hold on the page and break in practice.
An investor who asked me how to tell if the cash flow in a pitch deck is realistic was asking the right question. The follow-up, how to tell when a broker is not being straight, needs a reframe before it becomes useful. A broker is paid to present, not to protect you. Most of what misleads in a deck is framing and omission rather than fraud: the favorable comp shown and the unfavorable one left out, the expense line set at a number the current owner never achieved, the timeline drawn without the friction that lease-up actually carries. Presented, not protected. Once you hold the deck that way, you stop looking for lies and start looking for the assumptions carrying more weight than the market has agreed to.
Where optimism does the work
Start with rent. A pro forma does not overstate cash flow by inventing income. It does it by assuming a rent trajectory the submarket has not delivered and a tenant base cannot absorb. Compare the assumed growth against the actual comps and the property’s own history, then run the rents against local incomes. When the presented rent sits above what the market has produced and what tenants can pay, the cash flow above it is borrowed from a future that has not arrived.
Then read the expenses, which is where realism is easiest to bury. Compare the operating expenses in the pro forma against the trailing twelve months, not against a marketing summary. Taxes often reassess at the new basis after a sale, and many decks hold them near the seller’s old number. Insurance has moved materially in several markets, and a deck built on last cycle’s premium understates the true carry. Ask whether replacement reserves are actually funded or merely presented as a line. An expense ratio that looks impressively low is not efficiency. It is often a number the property has never run at.
Then the cap rates, because a single exit assumption can carry an entire return. When the exit cap is set below the entry cap, the model is counting on compression to bail out the deal, and compression is not something the sponsor controls. When the entry cap sits below the cost of debt, the deal is in negative leverage on day one, and the day-one cash flow exists only because value-add execution has not yet been tested.
Then the debt, measured against the business plan rather than in isolation. Floating-rate debt with a rate cap is a liquidity assumption with an expiration date. Ask what the cap notional amount, tenor, and strike price is to determine if it covers the full loan amount through its tenor. Confirm if the returns are boosted by a refinance that may or may not materialize.
The assumption that hides in the timeline
A while back I reviewed a value-add deck that passed every eye test. The rent assumptions were defensible against comps. The expenses reconciled to the trailing statements. The debt was structured sensibly. On the numbers alone, it read clean.
The buried assumption was the stabilization timeline. The plan presented a compressed window to renovate the units, lease them, and reach stabilized occupancy, and it modeled the property as if that window would hold. It did not account for realistic renovation pace, the downtime as units turned, or the absorption the submarket could actually deliver. Every dollar of the presented cash flow assumed the property was already full on a schedule the field had no reason to honor.
Change that one input, and the deal changes. The reserve gets consumed before the income arrives. The distributions that were modeled do not appear on time. The exit, which assumed stabilization had already happened, depends on a starting point that never occurred. Nothing in the arithmetic was wrong. The timeline was doing work the property could not perform.
The test worth running
The realism test asks one thing: which single assumption is carrying the deal, and what happens to you if that assumption is wrong. Find the load-bearing input. Then stress it. Hold rent growth flat, move the exit cap up, slip the stabilization by a year, and see whether the deal survives or whether the equity does. A deal that only works in the presented case is not a conservative deal. It is a bet on the exact case being right.
And when the sponsor pushes back on the stress test, watch how they behave. Do not accept a polished deck or a recognizable name as the answer. Ask how they respond when the model is questioned, because that is the behavior you will be depending on when reality tests the assumptions for you.
Closing thought
A clean model earns your attention. It does not earn your capital. Before you fund a deal, find the assumption the whole thing rests on, ask what the market and the operator has actually delivered against it, and ask who absorbs the shortfall if it does not hold. If the honest answer to that last question is you, price it accordingly.
Vessi Kapoulian
Breaking down multifamily underwriting one step at a time to create educated and empowered investors
P.S. If you would like a second set of eyes on a deal or want to sharpen your underwriting through a risk lens, feel free to connect with me.
P.P.S. And if you want to go deeper into analyzing multifamily investments step by step, my Mastering Multifamily Underwriting book and the Mastering Multifamily Underwriting program walk through this process in plain English, from acquisition to exit.