Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis. What : Shares of heavy construction products supplier Texas Industries ( NYS: TXI ) cemented big gains of as much as 12% following an upgrade from research firm Sidoti. So what : In a report released earlier today, Sidoti upgraded Texas Industries to "buy" from "neutral." The upgrade follows TXI's first-quarter earnings release from three weeks ago that saw the company miss Wall Street's earnings estimates by reporting a wider-than-expected loss, despite noting that shipments are improving, pricing is stabilizing, and margins are showing signs of correcting in the right direction. Now what : As usual, it's rarely worth paying much credence to the one-day pops and drops that are caused by analyst upgrades and downgrades as they don't often play into the long-term scheme of an investment.