Summary and review ofLower Costs, Higher Returns: My Path to Index Investing

Reviewed by Diario de un Inversor · UpdatedJune 13, 2026

Our review

Unai Ansejo holds an unusual credential for writing about index investing in Spain: he is co-founder of Indexa Capital, the country's largest robo-advisor by assets under management, which gives his account far more weight than a standard popularizing essay. The book traces his personal journey from traditional active management to the conviction that costs are the only factor investors can control with certainty — and that minimizing them is the most reliable lever for improving long-term net returns. Ansejo dismantles several persistent myths with historical data: that active managers systematically beat their benchmark, that market timing is predictable, or that product complexity is a proxy for better performance. The tone is conversational and autobiographical rather than academic, which aids readability but limits rigor in certain sections. Technically sophisticated readers familiar with Bogle or Fama will find familiar arguments. Where the book delivers genuine added value is in its Spanish contextualization: comparative fee analysis across domestic fund managers, the tax treatment of index funds in Spain, and the story of building a robo-advisor in a CNMV-regulated market are perspectives hard to find in Anglo-Saxon literature.

Key takeaways

• The management fee is the only component of investment returns the investor can control precisely; reducing it by 1% annually compounds into a substantial difference over 20 to 30 years.
• Actively managed funds do not consistently outperform their benchmarks, especially after costs are deducted.
• Global geographic diversification through index funds reduces country-specific risk without requiring individual stock analysis.
• A robo-advisor lowers the entry barrier to diversified portfolios for investors with modest capital.

Fact

Indexa Capital, co-founded by Ansejo in 2015, surpassed €2 billion in assets under management before 2023, making it the largest robo-advisor in Spain.