Hugo Bui

01  ·  Air quality  ·  2025 to now

CLEAR25

Canadian Lead-Time Early Air Response. Built with Ryan Zander.

In June 2023 Toronto's sky turned orange and PM2.5 hit 241 µg/m³, the highest reading the city has on record. The fires had been burning in Québec since May. The sensors between there and here had been reading the smoke the whole time. Nobody had turned those readings into a warning.

CLEAR25 is four systems that answer one question: how early can you know?

The first version drew a radius around Toronto and failed. It called every winter inversion a wildfire and slept through the events that mattered. Smoke doesn't travel as a circle, it travels as a sequence, and that's the whole system now.

02  ·  Markets  ·  2021 to now

Systematic trading

Value investing, and the backtests that keep me honest about it.

I started investing at ten and have run the portfolio myself since, up 83% over five years on a balanced value approach. Slow, boring, and the returns come from not doing anything stupid.

The research side is the part I actually enjoy. I build backtesting systems in Python and run strategies against years of minute-level data, testing entry timing, session effects, and filters to see which edges hold up once real costs are in. Most collapse immediately. That's the useful result, and it's the same instinct that made me throw out my first smoke model.

03  ·  Teaching  ·  2024 to now

HugoPrep

Entrance exam and interview preparation for University of Toronto Schools.

I sat the UTS entrance exam and got in, which is most of why I can teach it. HugoPrep is the practice I built around that: lesson plans, past paper breakdowns, interview drills and a student dashboard, plus the site and the marketing behind it.

I also work as a teaching assistant at Brain Power, presenting to and coaching prospective UTS students through their entrance interviews, and I tutor kids aged 6 to 12 in English, math and science privately. The tutoring is the part that taught me the most, mostly because a nine-year-old will tell you immediately when your explanation is bad.

04  ·  Small ventures  ·  2021 to 2025

Things I sold

A candy business, and two pitch competitions I probably shouldn't have won.

I bought candy wholesale and sold it to my school community. That meant forecasting demand, managing stock, setting prices, and eating the cost when I got any of it wrong. I got a lot of it wrong. It's the most useful business education I've had, and it cost about the price of a bulk order of sour keys.

Before that: first place in my Grade 5 Dragon's Den pitching competition, and first place in a Grade 6 investing competition with 30% returns over four months. Neither is a serious credential. Both are why I'm comfortable standing in front of a room and defending a number.