Following two "weaker" quarters in a row, Abiomed shares have become something of a "show-me story" until the company demonstrates it can start to reaccelerate growth sustainably, William Blair analyst Margaret Kaczor tells investors in a research note. The analyst, however, believes there is room for Abiomed's growth to reaccelerate to 20%-plus, though she admits this is now more likely in fiscal 2021 once the company's investments can come to fruition and new product launches can have a more material impact. With the stock at 8.8 times her 2020 revenue estimate, Kaczor keeps an Outperform rating on Abiomed.