Everyone is talking about Nvidia. Just 2 years ago the stock was worth a mere $400 billion. Now, depending on the time of day, it is worth somewhere around $3 trillion and was briefly the most valuable company in the world. Investors should not overcomplicate things here: Nvidia and the broader AI theme are in the midst of a speculative mania.

Of course, we have been here before. Investment stories, much like the current one, can be intoxicating and lure every last investor into the trade. During such times, diversification seems unnecessary. Who wants it when “one and done” portfolio decisions look so easy? Yet, investors invariably pay heavily for having taken on concentrated risk exposures. The late 1990s are a prime example.

At times like this, it is always useful to revisit the role of the portfolio manager: why do clients pay us to manage their wealth? It is not for flawless clairvoyance. Rather, we are paid to anticipate probable risks, prepare for opportunities and, importantly, not lose our proverbial minds when everyone else has lost theirs.