On Tuesday, there was an apparent change in psychology among investors that went beyond the modest declines in the major market averages. Even though most benchmarks fell only by half a percent or so, many formerly high-flying momentum stocks came crashing back to earth, especially those in the hydrogen fuel-cell arena. Yet some stocks still managed to climb even on a tough day, and Knightsbridge Tankers (NASDAQ: VLCCF), PowerSecure International (POWR.DL), and Zogenix (ZGNX) were among the best performers on the day.

Knightsbridge climbed almost 14% after receiving an analyst upgrade from Global Hunter Securities. The oil and dry-bulk shipping company had said on Monday that it would buy six Capesize bulk carriers from Frontline 2012, in which Frontline Ltd. (FRO -4.87%) has a stake and which Frontline CEO John Fredriksen also leads, and Karpasia, which is controlled by a trust for the benefit of Fredriksen's immediate family. The deal involves paying a total of $360 million, with more than half coming in Knightsbridge stock valued at $10 per share. The move fits with Knightsbridge's strategic plan to take advantage of what it sees as a recovery in dry-bulk shipping, and if it's right, the new vessels should help it capitalize well.

PowerSecure gained 9% after the utility- and energy-technology supplier reported strong fourth-quarter earnings last night. Sales soared 57% during the quarter, with strongest growth in its energy-efficiency and utility-infrastructure areas. With record levels of backlog, a strong balance sheet, and synergies from recent acquisitions, PowerSecure believes that 2014 has the potential to be an even better year for the company and its stock. The company also got an upgrade from analysts at Maxim Group this morning, adding to the positive sentiment surrounding PowerSecure.

Zogenix rose almost 12%, regaining just about all the ground the drugmaker lost last week. Last Thursday, Zogenix plunged 15% after reporting poor earnings. But the bigger question mark for the company is whether its FDA-approved drug Zohydro, a painkiller that has raised huge amounts of controversy, will end up having its approval revoked. Organizations have been lobbying against Zohydro, arguing that it is too dangerous. Yet with the FDA having already overruled the objections of its advisory committee in granting approval last year, investors are apparently feeling somewhat more secure that the regulatory agency won't act hastily to reverse course at this time.