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Cash Burn

Cash Burn (also known as 'Burn Rate') is the rate at which a company depletes its cash reserves to fund its operations before it can generate positive cash flow from its business activities. Think of it as a financial bonfire: a company is “burning” through its pile of cash to cover salaries, rent, marketing, and other expenses. This metric is especially crucial for unprofitable companies, particularly startups and high-growth technology firms, which often rely on investor capital to stay afloat. A high cash burn isn't automatically a death sentence; many successful companies burned through cash in their early days to scale up. However, it’s a critical indicator of a company's financial health and its short-term survival prospects. For an investor, understanding the cash burn rate helps answer the most pressing question for a young company: How long can it last before the money runs out?

Why Does Cash Burn Matter?

Imagine you're on a road trip across a desert with a limited amount of fuel and no gas stations in sight. The speed at which your car consumes fuel is your burn rate. Knowing this rate tells you exactly how far you can go before you're stranded. For a company, cash is fuel, and the cash burn rate determines its runway—the amount of time it has before it runs out of money and faces a potential shutdown. This makes cash burn a vital sign for several reasons:

Calculating and Interpreting the Burn

Calculating the burn rate is straightforward and reveals a company's financial trajectory. It's usually measured on a monthly basis.

Net Burn vs. Gross Burn

It's useful to distinguish between two types of burn:

The Runway Calculation

Once you know the net burn, you can calculate the company's runway.

  1. Step 1: Find the Net Burn Rate. Look at the company's cash flow statement.
    • Formula: Net Burn = (Cash at Start of Period - Cash at End of Period) / Number of Months
    • Example: A company starts the year with $2 million in cash. After 6 months, it has $1.1 million.
    • Cash Burned = $2,000,000 - $1,100,000 = $900,000
    • Monthly Net Burn = $900,000 / 6 months = $150,000 per month.
  2. Step 2: Calculate the Runway.
    • Formula: Runway (in months) = Total Cash Remaining / Monthly Net Burn
    • Example: With $1.1 million remaining and a burn of $150,000/month:
    • Runway = $1,100,000 / $150,000 = 7.3 months.

This company has just over 7 months to either become profitable or secure more funding.

A Value Investor's Take on Cash Burn

For a value investor, a company with a high cash burn is often guilty until proven innocent. The core philosophy of value investing is to buy wonderful businesses at fair prices, and a wonderful business, by definition, should be able to sustain itself without constantly asking investors for more cash.

Red Flags to Watch For

When is it (Maybe) Okay?

Not all cash burn is created equal. In some specific cases, a temporary burn can be a strategic investment in future value.

The Bottom Line: As an investor, your goal is to find businesses that can generate cash for you, not the other way around. While young, innovative companies often need to burn cash to get started, a prudent investor always scrutinizes the burn rate, calculates the runway, and demands a clear and convincing plan for reaching profitability.