MOIC (Multiple on Invested Capital) is total value returned divided by capital invested, also called the multiple of invested capital or, at the fund level, TVPI. It is a pure measure of how many times the money was returned, with no regard to time, which is why it is also known as the cash-on-cash multiple. Put in a dollar, get three back, and the MOIC is 3.0x.
Why it matters
MOIC answers the question "how many dollars did we make per dollar in," the complement to IRR's "how fast." Together they describe a return completely: magnitude and speed. A deal can post a striking IRR on a thin MOIC, or a modest IRR on a large MOIC, and only seeing both tells you which return actually moved the fund.
Equity in, equity out
Put in $60M of equity, return $180M at exit, and the MOIC is 3.0x. That same 3.0x is roughly a 25% IRR over a five-year hold. Stretch the hold and the MOIC is unchanged while the IRR drifts down, which is exactly why the two numbers belong side by side.
The common mistake
Comparing MOICs across very different hold periods without looking at IRR. A 2.0x in three years and a 2.0x in eight years are the same multiple but very different annualized returns. MOIC tells you the size of the win; IRR tells you whether it came fast enough to matter to the fund's overall performance.