Shares rose 1.63% to 30.49p in morning trading.
The Yorkshire –based polyhalite miner is likely to be included since its market value of £1.2bn is almost double the average of those companies it will replace.
The company’s share price has jumped 58.75% in the year to date as investors have turned more positive on its Yorkshire polyhalite mine after a successful £1.2bn fundraise late last year to support the first phase of development of the project.
Some had doubted the project would ever make it off the drawing board given the complexity of the engineering work planned.
In a first quarter update in March, Sirius said it was making “good progress” in clearing the conditions outlined in the project's planning agreements. The £1bn first phase of the Woodsmith fertiliser mine development is on time and on budget, it said.
Sirius a favourite among retail investors on AIM, says Hargreaves Lansdown...
Nicholas Hyett, equity analyst at Hargreaves Lansdown, said Sirius has “long been a favorite among retail investors on the AIM market”.
“With plans to build a huge mining facility directly under a National Park, many were sceptical that the project would ever get off the ground,” Hyett added.
“However, regulatory approval is now in the bag and several large investors are on board. The move to the main market and FTSE 250 suggests there may now be appetite for the project among the large institutions who are unable to invest in AIM stocks.”
Richard Knights at Liberum, who visited the site recently, said the company’s chief marketing officer described the change of mood of potential offtake partners as “night and day” once they knew funding was arranged.
Knights added that a major offtake partner is what the shares need to push on further, but talks are underway with a number of potential of groups.
Other FTSE 250 first-timers in reshuffle...
Other first-timers joining Sirius in the FTSE 250 are likely to be aircraft lessor, airline and energy group Stobart Group Ltd (LON:STOB) with a market value currently of £991mln and giant US investment group Pershing Square Holdings.
On the FTSE 100, Hikma Pharmaceuticals plc (LON:HIK) and Intu Properties plc (LON:INTU) are set to be relegated to the FTSE 250, with outsourcer G4S plc (LON:GFS) and industrial real estate investor Segro plc (LON:SGRO) taking their places.