The satellite radio provider is up 45% since bottoming out last month. There is still more potential upside.One of this year's biggest laggards is showing signs of life this summer. Shares of Sirius XM Holdings (SIRI -1.84%) have soared 45% since bottoming out in June. It's a big jump for any stock, but the satellite radio provider is still trading 35% lower so far in 2024.The stock has been on the move lately. It's going to be even more volatile this week. Sirius XM reports its second-quarter results on Th ...