This should have a positive impact on a revised mine plan expected in mid-2016, suggests analyst Matthew O'Keefe.
The project is fully funded to production which should average 1.6 million carats per year over a 20-year mine life.
Earlier, Stornoway said it had increased the indicated resource at Renard 2 by 16% to 21.6 million carats by converting lower class inferred material to a depth of 700 metres, while the overall indicated resource now stands at 30.2 million carats, including reserves.
The mining plan has been revised to reflect the increase.
The firm also told investors there was substantial new exploration potential at both Renard 2 and 3, which both remain open.
O'Keefe said an updated mine plan, expected Q2/16 just before production startup, is now under development and will incorporate the increased indicated resources.
"It is expected to include a deepening of the R2 and R3 pits, a deepening of the underground mine infrastructure and inclusion of the indicated resource at R65 via open pit mining. No material changes to our model expected at this time as we have already incorporated deeper mining and the inclusion of R65."
The broker keeps its $1.30 price target on what it calls a "high risk" stock. The current price is C$0.72.
"Stornoway appears attractively priced trading at 0.41x our NAV. As the company nears production, we would expect the stock to rise and our multiple to expand towards its diamond producing peers that currently trade at an average of 0.57x NAV," it adds.