https://inflectionquant.com/tags/brents-method/Recent content in Brent's Method on Inflection QuantHugoen-usThu, 09 Apr 2026 00:00:00 +0000https://inflectionquant.com/articles/newton_vs_brent_vol_solver/Thu, 09 Apr 2026 00:00:00 +0000https://inflectionquant.com/articles/newton_vs_brent_vol_solver/<h2 id="why-this-matters">Why This Matters</h2> <p>I plan to write about calibrating a full volatility surface, and that work rests on a clear understanding of a simpler problem: solving for implied vol from a single option price. At its core, this is a root-finding problem. Given a market quote, we look for the volatility at which the model price matches the market price. A common algorithm for this is Newton&rsquo;s method. I learned it in class, saw it in textbooks, and implemented it in the traders&rsquo; tools at work. Most of the time it just works. I knew convergence wasn&rsquo;t guaranteed, but that stayed abstract until I hit an edge case.</p>