Meme-stock ETF is back from the dead. Last time, its launch coincided with the 2021 market top.

By Joseph Adinolfi and James RogersThe ETF's biggest holding is Opendoor, a name that has sparked comparisons with the meme-stock explosion of 2021The resurrected meme-stock ETF began trading on Wednesday, with Opendoor Technologies as its biggest holding.Roundhill Investments has resurrected an exc…