Investment decisions can become incredibly complicated, and in the case of successful startups, minute changes to ownership stakes can equate to millions of dollars. Thankfully, there’s a simple rule of thumb we can use to work out whether or not we think an investment opportunity is worthwhile.

An investment deal is worthwhile if you believe the deal will increase the value of your shares in the long-term by more than it reduced it in the short-term.

Most founders start out owning their company.

But to grow as quickly as possible, you’ll need investment, and to secure the capital you’ll need, your investors will want to own a part of your company.

The faster you grow, the greater your burn rate becomes, and the more capital you’ll...