Retail investors spent 2025 doubling down on AIinfrastructure, European defence, and frontier quantum computing, highlighting themarket’s most crowded trades and fastest-growing favourites on trading andinvesting platform eToro. The latest eToro data shows that investors shifted from pure AI“hype” names to companies tied to hard assets, long-term contracts, and clearerrevenue visibility.AI Infrastructure Drives Retail PositioningAI data centres and cloud infrastructure sat at thecenter of retail positioning in 2025, as investors focused on the companiespowering large-scale AI deployment rather than just the headline chip makers.Nebius Group, an AI infrastructure provider, emerged as the standout story,recording a 328% increase in holders on eToro and topping the platform’s global“top risers” list for the year.Oracle, another major player in data infrastructure,ranked third with a 228% year-on-year jump in holders, underlining how retailinvestors targeted firms tied directly to data centre buildout and enterpriseAI adoption.Nvidia remained the single most held stock on theplatform and still added 21% more holders over the year, while Meta, which haspositioned itself as a key AI technology player, grew its holder base by 19%.European Defence Becomes StructuralDefence names listed in Europe also moved into focusas a structural allocation rather than a tactical trade for many retailinvestors.Four European defence groups appeared in the global“top risers” table on eToro: Italy’s Leonardo in fourth place with a 209% risein holders, France’s Thales in seventh with a 167% increase, Germany’sRheinmetall in eighth with 165%, and the UK’s BAE Systems in tenth with 141%growth in holders. Their ascent came against the backdrop of a proposed€800 billion plan by the European Union to rearm the continent, which hassharpened attention on defence spending and procurement pipelines.Retail Portfolios on eToro in 2025Alongside AI and defence, quantum computing began toregister as a recognisable theme in retail portfolios on eToro in 2025. Quantumcomputer makers IonQ and D-Wave Quantum both made the global risers list,securing sixth and ninth place respectively, with increases in holders of 169%and 149%.Healthcare stocks produced two contrasting stories inretail behaviour over 2025. UnitedHealth and Hims & Hers Health rankedamong the most popular names on eToro, reflecting steady demand forhealth-related exposure despite market volatility.UnitedHealth, which appearedas a top riser in both the second and third quarters, finished the year as thestock with the second-largest increase in holders at 273%. This article was written by Jared Kirui at www.financemagnates.com.