There are essentially two or three ways you can answer this question. You can tell a story about how you became interested in private equity, or you can list a number of reasons you’re interested in private equity, and back them up with examples from work or even school. You can also combine these two methods into one answer.
For example, if you want to tell a story, you can talk about how your interest in finance was sparked by a passion for investing, perhaps developed while taking finance courses or working with an investment club. You can also speak to your investment banking work experience and / or deal experience – or any other related experience – and elaborate on how that generated an interest in understanding the strategic rationale behind each deal and if it made sense from both the buyer’s and seller’s perspective.
If you have any experience with strategy, such as consulting, you can speak to how you really enjoyed finding the best strategy for different firms, and how you became more interested in analyzing and viewing growth from the owner’s perspective.
All this segueways nicely into your current interest in private equity.
Alternatively, or in addition to this, you can list a few concrete reasons you’re interested in private equity, such as being passionate about investing or company growth/strategy, and a desire to take a longer term perspective by following portfolio companies closely rather than moving onto the next deal like in investment banking.