<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Factor Models | Stefano Blando</title><link>https://stefano-blando.github.io/en/tags/factor-models/</link><atom:link href="https://stefano-blando.github.io/en/tags/factor-models/index.xml" rel="self" type="application/rss+xml"/><description>Factor Models</description><generator>HugoBlox Kit (https://hugoblox.com)</generator><language>en-US</language><lastBuildDate>Fri, 06 Mar 2026 00:00:00 +0000</lastBuildDate><image><url>https://stefano-blando.github.io/media/icon_hu_8d0dee6c10a3c598.png</url><title>Factor Models</title><link>https://stefano-blando.github.io/en/tags/factor-models/</link></image><item><title>Robust Portfolio Optimization under Systematic Market Disruptions (PFSE)</title><link>https://stefano-blando.github.io/en/projects/robust-portfolio-optimization/</link><pubDate>Fri, 06 Mar 2026 00:00:00 +0000</pubDate><guid>https://stefano-blando.github.io/en/projects/robust-portfolio-optimization/</guid><description>&lt;p&gt;This project introduces the &lt;strong&gt;Parallel Factor Space Estimator (PFSE)&lt;/strong&gt;, a hybrid framework for robust covariance estimation that resolves a fundamental trade-off in institutional portfolio management: traditional robust estimators (MCD, Tyler) offer strong statistical guarantees but are computationally infeasible for daily rebalancing of 100+ assets, while efficient methods (Ledoit-Wolf, sample covariance) have zero breakdown point against systematic contamination.&lt;/p&gt;
&lt;p&gt;PFSE exploits a structural insight: during systematic market disruptions — flash crashes, monetary policy shocks, crisis contagion — extreme movements propagate through &lt;strong&gt;common factors&lt;/strong&gt;, not idiosyncratic components. By concentrating robust estimation in reduced k-dimensional factor space (k=5 versus p=100–1000), PFSE inherits 25% breakdown point from MCD while achieving &lt;strong&gt;32× computational speedup&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;&lt;em&gt;Work with Alessio Farcomeni (University of Roma Tor Vergata). Submitted to Computational Economics (Springer), March 2026.&lt;/em&gt;&lt;/p&gt;
&lt;h2 id="key-results"&gt;Key Results&lt;/h2&gt;
&lt;p&gt;Validated through three complementary stages:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;&lt;strong&gt;Monte Carlo (p=100, ε=10% contamination):&lt;/strong&gt; PFSE Sharpe 1.42 vs 0.96 for sample covariance — maintains 97% of clean-data performance while sample covariance degrades 31%&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;S&amp;amp;P 500 backtest (2015–2025):&lt;/strong&gt; Out-of-sample Sharpe 1.87 vs 1.63 (+14.7%), max drawdown −24.3% vs −34.1% (−29%) during COVID-19, turnover −42%&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Five stress scenarios:&lt;/strong&gt; PFSE rank-1 across all scenarios, average Sharpe 1.67 vs 1.39 (+20%), lowest performance variability (CoV 0.041 vs 0.064)&lt;/li&gt;
&lt;li&gt;&lt;strong&gt;Economic value:&lt;/strong&gt; $72M normal-period + $93M stress-period benefits per $1B portfolio, benefit-cost ratio 31:1&lt;/li&gt;
&lt;/ul&gt;
&lt;h2 id="interactive-explorer"&gt;Interactive Explorer&lt;/h2&gt;
&lt;p&gt;The interactive app lets you explore the full results: run the PFSE estimation algorithm live, compare methods under increasing contamination levels, examine computational scalability, and inspect S&amp;amp;P 500 cumulative returns across all four market regimes.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;
&lt;/strong&gt;&lt;/p&gt;</description></item></channel></rss>