Attribute concentration of foreign investor portfolios to retail versus institutional investors

Ascertain whether the observed concentration of aggregated foreign investor stock portfolios in the Nasdaq Nordic Helsinki market is primarily driven by foreign retail investors or by foreign institutional investors.

Background

The paper documents that foreign investors’ aggregated portfolios are more concentrated than those of Finnish investors, especially during 2001–2011. Understanding whether this concentration is predominantly due to retail or institutional behavior would clarify the drivers of foreign investment patterns.

Because investor-type labels are not available for many foreign accounts (due to nominee registration), the authors explicitly state they cannot determine whether retail or institutional foreign investors are responsible for the heightened concentration.

References

The conclusion is rather different for foreign investors and unfortunately the data we have does not allow us to conclude whether the concentration of foreign investors is due investment choices of retail of institutional foreign investors.

— Heterogeneity of household stock portfolios in a national market (2503.17778 - Milazzo et al., 22 Mar 2025) in Section 5, Discussion and conclusions