Large investment funds run by groups such as Fidelity and T Rowe Price are being forced to offload shares to avoid getting into trouble with US tax authorities, as this year’s lopsided stock market rally has pushed them up against strict limits requiring them to maintain diversified portfolios.
The Internal Revenue Service requires that any “regulated investment company” — which includes the vast majority of mutual funds and exchange traded funds — keep the combined weight of large holdings to less than 50 per cent of their overall portfolio.
https://www.ft.com/content/05b21f37-bf3f-436c-9544-dcacf675afee