As previously reported, MKM Partners analyst Rob Sanderson upgraded Twitter to Buy from Neutral, telling investors that the service is “here to stay,” citing its rebounding user growth and continued turnaround progress. Sanderson, who sees potential upside in monetization gains, thinks the next phase of Twitter’s turnaround may have less EBITDA upside, but also less execution risk, he tells investors in a research note. He set a $40 price target on Twitter shares, which closed yesterday at $31.54.