A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
For questions *about* being a quant, akin to questions on programmers.SE vs. SO. Includes soft questions, career-related questions, questions about best practices, etc.
Questions about Interactive Brokers, a retail brokerage, and its API for automated trading.
easy to define qualitatively (the easiness to buy or sell an asset), but difficult to measure.
A debt security that doesn't pay interest (a coupon) but is traded at a deep discount, rendering profit at maturity when the bond is redeemed for its full face value.
forecast the prices direction based on the past market data study.