An investor in IP (specifically patents) is any person or entity that acquires or otherwise obtains an equity position in a patent portfolio, with the goal of earning a financial return on the investment.
An IP investor includes not only those that acquire an interest in patent portfolios, but also attorneys that enforce and brokers that sell patent portfolios, on a contingency-fee basis.
As such, an IP investor is really a team comprised of those with financial means to acquire patent assets, and those with the specialized knowledge to actually monetize the investment, either through enforcement or a sale.
To become a successful IP investor, you must assemble a balanced team with both financial backing and specialized knowledge. Before you make an investment in IP, ask yourself if you have the right team in place that can carry you through the full cycle from investment to monetization.