Shares of Quantumscape (QS -3.72%) had a down day Thursday even as the broader market rallied. While there was no company-specific news about the solid-state battery maker, traders apparently reacted to disappointing earnings reports from Rivian (RIVN -25.60%) and Lucid (LCID -16.76%). Quantumscape shares closed Thursday down by 3.6% after having been off by as much as 5% earlier in the session. Meanwhile, shares of both of those unprofitable EV start-ups fell by double-digit percentages. The EV market down ...