The Portfolio Theory of Friendship
Teresa said something to me once that I couldn't stop thinking about. Friendships, she said, are like a portfolio.
At first I thought it was a very Teresa thing to say. But the more I sat with it, the more it explained something I'd never quite had language for: why some friendships feel effortless and complete, why others are wonderful but limited, and why I used to feel vaguely guilty that no single friend in my life checked every box.
That guilt, it turns out, was the actual problem. Not the friendships themselves.
Not every friend needs to check every box
Here's the core of the theory. In an investment portfolio, you don't put all your money in one stock and expect it to cover every possible outcome. You diversify. Some investments are stable and reliable. Some are higher risk with higher reward. Different assets serve different functions, and the whole portfolio works because of that variety, not in spite of it.
Friendship works the same way, and most of us were never told that directly. We were handed a cultural expectation that a best friend should be everything: your confidant, your hype woman, your intellectual sparring partner, your fun Friday night plan, your person who shows up in a crisis at 2am. And when one friend can't be all of that, we quietly wonder if the friendship is somehow lacking.
It isn't. Some friends are your fun friends, and that's enough. Some friends are your thought partners, the ones you call to talk through a hard decision, even if you never see them outside of that context. Some are what Teresa calls high beta, higher risk, higher reward, a little unpredictable, but worth it for what they bring when they're good. None of these categories are lesser. They're just different assets doing different jobs.
What career and motherhood actually do to your friend group
Two forces reliably reshuffle a friend portfolio more than almost anything else: career acceleration and becoming a mother. And what's interesting is that career success doesn't uniformly damage friendships the way people sometimes assume. For Teresa, it was closer to what she called a K-shaped effect. Some friendships got stronger, because there was suddenly more to relate to, more to be a thought partner about. Others, ones that were never really built around shared ambition to begin with, simply revealed how wide the values gap actually was, and those quietly fell away.
Motherhood does something similar but different. It doesn't just reveal existing gaps, it creates new constraints almost overnight. Suddenly your calendar has less give in it. The friend who wants to catch up over a three-hour dinner might not be the friend who fits into the life you have now, not because you don't value them, but because the portfolio itself needs to shift toward what actually functions with your real bandwidth.
This is not a tragedy. It's rebalancing. Portfolios are supposed to change as your life changes. The mistake is treating a shift in your friend portfolio as a personal failure, rather than what it actually is: an adjustment to new inputs.
The friend who was an hour and fifteen minutes late
Teresa has a story that captures exactly how these shifts actually happen in practice. A friendship from earlier in her New York years, someone genuinely useful and kind when she was first finding her footing in the city, had a habit of being late. Not fashionably late. Late in a way that eventually became the whole relationship.
The breaking point was a dinner reservation Teresa had been excited about. She arrived on time. Ten minutes passed. Twenty. Thirty. No response to texts or calls. She ordered a glass of wine, ordered food, called her mom, and settled in. Her friend arrived an hour and fifteen minutes later, with an explanation about the subway that didn't remotely cover the gap.
What's notable isn't the lateness itself. It's what Teresa said afterward, with real honesty: she isn't proud of how she handled it. She ghosted the friendship rather than naming what had happened directly. And in hindsight, the deeper issue wasn't really the timing. It was that the friendship had started taking more than it was giving, and the lateness was simply the most visible symptom of an imbalance that had been building for a while.
You can't hold someone to a standard you never communicated
This is the part of the conversation that cuts closest to the bone. Most friendship rifts are not really betrayals. They're expectations that were never actually stated out loud, and then quietly resented when they went unmet.
You expected them to check in more. You expected them to remember the hard week you mentioned once, three weeks ago. You expected them to offer before you had to ask. None of that is unreasonable to want. But if it was never communicated, and never agreed to, holding someone accountable to it after the fact isn't really fair to either of you.
This reframes a lot of friendship pain in a useful way. Before writing someone off as having failed you, it's worth asking honestly: did I ever actually tell them what I needed? Sometimes the answer changes everything. Sometimes it doesn't, and you find out the relationship genuinely was taking more than it was giving. Both outcomes are useful information.
Not every relationship needs to be fifty-fifty
Here's a belief that took years to arrive at: friendships, like romantic relationships and work relationships, don't have to be perfectly even to be healthy. There will always be seasons where one person is giving a bit more and one is getting a bit more. That's normal, and it isn't inherently a problem.
The actual question worth asking is simpler: what am I getting from this relationship, and does it feel like enough? Sometimes the honest answer is that a friendship exists purely for fun, and that's genuinely enough. It doesn't need to double as a therapy session or a career-strategy meeting to have value. Other times the honest answer is that the giving has outpaced the getting for long enough that the relationship has become a net drain rather than something that adds to your life. Neither answer needs to be dramatic. It's information, not indictment.
The door doesn't have to slam
This is where the portfolio idea reaches its real conclusion. A portfolio isn't static. It's rebalanced constantly as your goals, your capacity, and your life change. A friendship shifting or fading isn't proof that it failed. It's proof that it did its job for the season it was in, and the portfolio moved on, the way portfolios are designed to.
That doesn't mean every door needs to close permanently. You can step back from a friendship, close the door for now, without locking it. If you find yourself thinking about someone you've drifted from, missing the specific thing that friendship gave you, that's worth paying attention to. Reach out. Let them self-select in or out. You don't have to make the decision for them by assuming you already know how they'd respond.
And when it comes to grudges specifically, there's one honest question worth sitting with: are you going to carry this until the day you die? If the answer is obviously no, it's worth asking who it's actually serving to carry it right now. Most people, most of the time, are doing the best they can with what they have. The mistakes that end friendships are rarely acts of malice. They're usually just two people operating on different, unspoken expectations.
Build the portfolio on purpose
The version of friendship that actually works isn't the one where a single person meets every need forever. It's a deliberate mix: people who challenge you, people who are just plain fun, people who show up in a crisis, people who share history even without shared ambition. None of them need to do all of it. That's the whole point.
And the mix is allowed to change. As your career accelerates, as you become a parent, as your capacity shifts, the portfolio should shift with you. That's not failure. That's exactly how it's supposed to work.
Want to hear the full conversation? Listen to Episode 110 of Rewritten: Real Talk for Working Moms Who Want It All on Apple Podcasts, Spotify, and YouTube.
If this resonated and you want support figuring out what actually matters to you as your life and priorities shift, I work with women one-on-one to do exactly that. Book a free consultation at reworkit.co/schedule-a-consultation.
Jess Wass is the Founder of Reworkit, a leadership development and coaching company, and co-host of Rewritten: Real Talk for Working Moms Who Want It All. She helps women ditch the script they were handed and build a life that's actually theirs.
