iRobot Corporation Stock Price and Value Analysis

The intrinsic value of a company is how much cash it can generate over its lifespan. If a business lasts for ten years and produces a million dollars of free cash profit every year, its intrinsic value is ten million dollars.

The present value of an investment is the price you must pay right now to earn that intrinsic value in however many years you want to wait. This of course depends on the rate of return you want for your investment.

You can't predict what a company will make in the future with perfect accuracy, but a company with a history of increasing its free cash flow every year is likely to do so over time. By projecting free cash flow into the future, you can calculate a fair price for the stock right now.

While most stocks are priced fairly, sometimes they go on sale. This calculation will help you decide that. You still have to figure out if it's a good investment, but bargains exist.

The safety margin of a stock helps you avoid risk.

Why? Because the discounted free cash flow analysis relies on estimates, discounting the fair price by a further safety margin gives you some wiggle room to be wrong about those estimates. Established companies with stable free cash flow growth need a small safety margin. Smaller and newer and riskier companies need a larger safety margin. A company with a lot of debt needs a larger safety margin and a company with a lot of equity needs less.

By investing in multiple companies and keeping a sensible safety margin, you can be pleasantly surprised by great companies outperforming your expectations and minimize the possibility of stagnation (or even loss) by companies which underperform.

The PE ratio measures the reported earnings of a company to its current stock price. While earnings are easy to manipulate on the balance sheet, this ratio gives you a sense of what buyers are willing to pay for the stock—what they believe it will do in the future.

Comparing a stock's PE to the average PE of companies in its industry gives you a sense of market sentiment about the stock and how well it fares financially. It's not the only number, nor the most important, but comparing similar companies is valuable. A ratio far above or below that of its peers is significant.

Industries are more specific than sectors, so companies within most industries are more similar than are companies within an industry. Be aware that the size and customers of companies are important to their prospects.

The PE ratio measures the reported earnings of a company to its current stock price. While earnings are easy to manipulate on the balance sheet, this ratio gives you a sense of what buyers are willing to pay for the stock—what they believe it will do in the future.

Comparing a stock's PE to the average PE of companies in its sector gives you a sense of market sentiment about the stock and how well it fares financially. It's not the only number, nor the most important, but comparing similar companies is valuable. A ratio far above or below that of its peers is significant.

Be aware that sectors are very broad, with many types of companies in the same sector.

The cash yield of a stock is the ratio of free cash per share—real dollars available after bringing in revenue and paying bills—to the current price of the stock. It's similar to the PE ratio, but it's less prone to manipulation through accounting practices.

In general, the less you have to pay to make more money, the better.

The free cash flow jitter of a stock measures how much the company's free cash flow varies from its historical trend, on average. While it's always nice to make more money than you expected, a company with predictable free cash flow is stable and good. A company with wild swings in its free cash flow warrants further research.

In general, the lower this number, the better.