Starting a business from scratch and having little money in the bank focuses your mind in a way that running a multibillion-dollar business never does. It brings the key drivers of performance into sharp relief. I promise.

My low point was after being reorganized out of running Merrill Lynch. That dismissal deeply contradicted my sense of fairness, since, at the time, my team and I had done what we were brought in to do: We had turned Merrill Lynch around from the depths of the financial crisis.

The Ellevest target client is the professional woman who either has her own money or has agency over her family's money. She is among the 75 million women in the U.S. workforce who want to take financial control and is looking for a straightforward way to achieve her dreams on her own terms.

If you aren't committed to diversity of thought, you have no business launching a startup.

We just haven't had enough women in senior roles on Wall Street overall - fewer women in the investment banking function overall as well.

We all know money is power. And women won't be equal with men until we are financially equal with men. Getting more money into the hands of women is good for women, but it's also good for their families, for the economy, and for society.

I have a very simple point of view, which is, I'm going to be alive for some amount of time; I don't know how long that's going to be. Then I'm going to be dead for a really, really long time. Right? You need to squeeze everything you can out of this time when you're alive.

We shouldn't think anyone needs a Ph.D. in advanced investing in order to begin to invest.

I wish I had known that that process of figuring out what you're good at, what you want to do, and where you want to have an impact is not a one-time exercise, but an ongoing one. Instead, I bought into success being an endpoint rather than a constant process.

One thing I never thought about in my big-company job? Cash flow. When your business has billions of dollars in revenue, you can make a lot of mistakes and still have a viable business. But in a startup, make a few hiring mistakes, and you can find yourself in real jeopardy fast.