2 papers
q-fin.PM2026
A Unified Theory of Ownership Concentration, Overlap, and Dependence
Miquel Noguer i Alonso, Iro Tasitsiomi
Ownership concentration is not a scalar. For a normalized investor-stock matrix , it has three irreducible layers: concentration across investors, concentration across stocks, a…
q-fin.TR2025
On the hidden costs of passive investing
Iro Tasitsiomi
Passive investing has gained immense popularity due to its low fees and the perceived simplicity of focusing on zero tracking error, rather than security selection. However, our an…