Its shares shot to a 4.5-year high of C63c at the end of January as the market digested its intersection of 1.7m at 393.33g/t gold from 225.85m in PE2019-22, the first drill hole of 2019 into the Eastern Gold Zone.
The company said the EGZ could be followed from surface to a vertical depth of 375m over a minimum strike length of at least 300m, with chairman Jacques Trottier saying at the time the goal of this year's programme was to target the higher-grade zone and trace it closer to surface.
Among further highlights reported yesterday, Amex intersected 5.85m at 24.06g/t, including 0.65m at 214.71g/t, which the company said verified vertical continuity in the near-surface portion of the system.
It also reported intersecting visible gold in the first 25m step-out hole testing the lateral extent of the high-grade zone.
Further results from PE2019-22 included visible gold in the original low grade zone and a second lower grade zone of 40m at 0.5g/t gold.
Amex has spent more than $9 million to date on exploration at Perron and said the current programme was aiming to provide a basis for a maiden resource estimate.
The company raised $552,000 (US$421,000) in an upsized placement in December at 8c per unit, for drilling at Perron and general working capital.
Its shares had spent much of 2018 below the 10c mark.
Amex lost 10c or about 16% yesterday to close at 52c, capitalising it at $24.3 million.