My first job in finance was in private banking at a large Swiss bank in New York. I was laid off after two years, and honestly I detested my boss. He lied to clients, and made promises he never intended to keep. Very unethical.

A couple of years later I was working at a large German bank in New York, also in private banking. I was more senior there, but as I also have a PhD I was accorded a lot more respect by the Germans I worked with, who practically worship doctorates.

We had a client who was a very prominent German family trust, and for some reason never articulated to me the trust needed to place $200 million in custody outside of our bank. We were the trustee. They suggested the Swiss bank that I had previously worked for, and they approached the New York office to discuss the deal. One of my German colleagues remembered that I had worked for this very bank, and as part of their due diligence asked me, knowing what I know about the New York branch, would I recommend them as custodian for our client. I asked who was the Swiss banker they were speaking to.

You guessed it — my ex boss.

I simply responded honestly, that he was untrustworthy and unethical, and told them a few instances where I knew for a fact that he had lied to our clients. My German colleague took notes, thanked me for my insights, and went back to the client to report. The next day he told me they intended to partner with an American bank.

Later that day a former Swiss colleague of mine called me “to say hello”. Along the way he wondered if I had heard about a custody deal between my current bank and my old employer. “Sure,” I told him. “I killed it.”

That was followed by about ten seconds of dead silence, before my friend burst out laughing. He thanked me for my honesty, and noted that this was a good lesson towards treating people ethically in business at all times, because in the end global finance is a very small world.