The stock market is taking a hit today. Most sectors are in the red. The S&P 500 (^GSPC -3.58%) shed more than 4% by late morning.But shares of luxury home furnishings company RH (RH -39.90%) are getting crushed. The company reported fourth-quarter earnings last night, but that's not the only thing driving the sell-off.RH stock was down an astounding 44.1% as of 10:43 a.m. ET. Here's why.First housing, now tariffsRH reported decent fourth-quarter results, with revenue increasing 10% and continued strong dem ...