Investment Portfolio
Portfolio
Dashboard
A documented investment process, built in public.
About
I'm Isaac Toffel, an Economics and Data Science student at Northeastern University, interested in equity research and asset management. This site documents how I think about portfolio construction, position sizing, and thesis-driven investing in my investment account.
I won't be right on every position. That's fine. What I want is a repeatable process: track decisions honestly, then check whether the outcome came from good reasoning or luck. This site is that record, in public.
Education
Northeastern University
Experience
State Street
Certification
CFA Level I Candidate, Feb 2027 sitting
Isaac Toffel
Framework
Portfolio as a System
I treat the portfolio as one system, not a pile of separate bets. Every position has a job. Sizing tracks how well it does that job, not how much I like the company. I'd rather concentrate capital where the upside is asymmetric than own a long list of names that just look interesting.
Two AI-labeled holdings can still fail for completely different reasons. NBIS's risk is hyperscalers undercutting independent GPU clouds on price. CBRS's risk is customer concentration, a handful of buyers deciding the outcome. Same label, different ways to lose, which is the diversification I actually care about. The portfolio keeps changing as positions prove or lose that case.
Discipline
Investment Policy
Position sizing
The book is concentrated single names, plus sector, commodity, and cash sleeves. There is no broad-market index position today. Individual equities are sized on conviction, volatility, thesis maturity, and correlation with what is already owned, generally targeting around 10% with a soft 11.5% ceiling unless I explicitly re-underwrite the thesis. A position stays because it keeps earning its size.
When I trim or sell
A position moving above target doesn't trigger an automatic sell. I treat it as a signal to review the thesis. If the thesis has gotten better, I re-underwrite and let the bigger weight stand. If price ran ahead of the thesis, I trim back toward target. I also cut a position when the thesis breaks, valuation outruns the evidence, a better idea shows up, or the size grows past what I want in my risk budget.