What is quant dev?

Quantitative development (quant dev) sits at the intersection of finance, mathematics, and programming. Quant developers build the software systems that financial institutions use to price assets, manage risk, and execute trading strategies — all using math and code instead of human intuition.

Think of it this way: a regular trader might say "I think Apple stock will go up." A quant says "based on these 12 statistical signals, there is a 58.3% probability of a positive return over the next 21 trading days, and here is the exact position size that maximizes return per unit of risk."

The financial building blocks

Before anything else, you need to understand what quants are actually working with.

Assets

An asset is anything you can buy or sell that has financial value. The main categories:

• Stocks (equities) — ownership shares in a company. When Apple does well, AAPL stock goes up.
• Bonds — loans you make to governments or companies. They pay you interest.
• Derivatives — contracts whose value derives from an underlying asset (like options, futures). This is where a lot of quant math lives.
• ETFs (Exchange-Traded Funds) — baskets of stocks that trade like a single stock. e.g. XLK tracks the entire technology sector.

Prices and returns

Quants almost never work with raw prices. They work with returns — the percentage change from one period to the next.

If a stock goes from $100 to $112:

• Return = (112 - 100) / 100 = 12%

Why returns instead of prices? Because $10 means very different things for a $20 stock vs a $2,000 stock. Returns make everything comparable.

Volatility

Volatility measures how wildly an asset's price swings. A stock that moves 1% per day is calm. One that moves 5% per day is wild. Mathematically, volatility is the standard deviation of returns, annualised.

This matters because: