The TSX-quoted gold miner listed on the premium segment of the LSE in June.

FTSE Russell is expected to confirm index membership changes on September 1 with changes effective from September 20.

Analysts at Barclays said FTSE inclusion "could lead to passive demand of ~10% of market capitalisation".

"We see index inclusion as one of a number of potential positive catalysts over the next 6-12 months, and ultimately see 37% upside to our 2350p price target as the company re-rates to trade in line with the global gold peers," said Barclays.

Endeavour has one other hurdle to clear to gain FTSE status: it must pass the minimum liquidity threshold of 0.025% of free float per month during the period from August 3 to the index decision date of September 1.

Barclays estimated the required liquidity equates to median daily trading volume of about 46,000 shares. Bloomberg data shows median daily liquidity has been 49,000 since June, and 68,000 in the last month, said Barclays.

Shares in Endeavour were up 10% on Tuesday morning UK time but fell back across the afternoon. Shares are currently valued at 1,670p, capitalising the company at £4.22 billion.