Stifel analyst Stanley Elliott said he sees shares of Summit Materials as meaningfully undervalued and still sees upside in the stock after yesterday's 14% move higher, which was prompted by reports that Cementos Argos proposed a merger with the company. With that said, Elliott told investors in a research note that he is not sure the sources of those reports are credible. "This feels like a rumor to get investors focused on Summit's portfolio and the value that is not currently reflected in equity markets," or a way to shift the discussion from challenges the company is currently facing, Elliott stated. His sum-of-the-parts analysis to help assess a potential takeout value points to a value of $23-$24 per share, added the analyst, who keeps a Buy rating and $23 target on Summit Materials shares.