Index compiler FTSE Russell confirmed late on Wednesday that Edinburgh investment giant Abrdn will be demoted from the FTSE 100 following a drop in its share price of more than 30% in the past month.

Abrdn only rejoined the index in December 2022.

Falling out of the FTSE 100 index can dampen demand for a company’s shares due to the huge role played in stock markets by giant “passive” funds that simply track the performance of the index.

Abrdn shares have fallen to around £1.64 to reduce the firm’s stock market value to about £3.2 billion.

“FTSE Russell, the global index provider, confirms today that Dechra Pharmaceuticals, Diploma, Hikma Pharmaceuticals and Marks and Spencer Group will be joining the FTSE 100 Index as a result of the September 2023 quarterly review,” said FTSE Russell.

“In the rebalance, Abrdn, Hiscox, Johnson Matthey and Persimmon will leave the FTSE 100 Index and enter the FTSE 250 Index.

“The rules-driven, impartial quarterly reviews ensure the indexes continue to portray an accurate reflection of the market they represent and form an essential component to the management of the indexes …

“All changes from this review will be implemented at the close of business on Friday, 15 September 2023 and take effect from the start of trading on Monday, 18 September 2023.”

On August 8, Abrdn said its assets under management and administration slipped 1% to £496 billion in the first half of 2023 as it reported net outflows “excluding liquidity” of £4.4 billion.

Abrdn said positive flows of £1.9 billion at its Interactive Investor (ii) business were “offset by outflows” in its investments unit and adviser business.

Abrdn shares fell as much as 11% on August 8 alone.