About
Isaac Toffel
Toffel Capital publishes research on my own investment account: portfolio papers, a thesis for each holding, a dated log of every decision, and time-weighted performance, including positions that lost money.
I don't manage money for anyone else. Performance is self-reported and has not been independently verified, and nothing here is investment advice.
Investment approach
Portfolio construction
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. Two AI-labelled holdings can still fail for completely different reasons: NBIS's risk is hyperscalers undercutting independent GPU clouds on price, while VST's is timing, because its long-term data-center contracts start later and until then it sells much of its output at market prices.
Position sizing
The book is concentrated single names, plus sector and commodity positions. There is no broad-market index position. Individual equities are sized on conviction, volatility, thesis maturity and correlation with what is already owned, generally around 10% with a soft 11.5% ceiling unless I explicitly re-underwrite the thesis.
Thesis review and exits
A position moving above target is a signal to review the thesis, not an automatic sale. If the thesis has improved, I re-underwrite and let the larger weight stand. If price ran ahead of the thesis, I trim toward target. I also sell when the thesis breaks, valuation outruns the evidence, a better idea appears, or the position grows past my risk budget.