Jefferies targets a punchy $25 for the shares, well over three times' the current price of at $7.30 - up 2.53% on the day.
Its candidate Crenezumab underpins the broker's valuatrion of the group, which is partnered with Genentech in a Phase III trial with data expected in the second half of 2020. The broker estimates US$4.4bn world wide peak sales for the drug by 2028 estimates for $16 a share net present value (NPV).
Analyst Peter Welford notes that ACIU has three other Phase Ib-IIa products for a pipeline providing a multitude of catalysts by 2018.
He reckons the biotech's below $300mln enterprise value (EV) substantially undervalues the group.
Last week the group confirmed that all key pipeline programmes were on-track, he adds.
"We still expect a further update on anti-Abeta vaccine ACI-24 by YE, with the 4th dose cohort ongoing in Phase I/IIa."
Welford adds: "We forecast cash to be adequate for burn well into 2019E, by which time a significant number of catalysts could crystallise value."