HONG KONG ( TheStreet) -- Euro Tech Holdings ( CLWT) was among the top gainers on the Nasdaq, surging more than 40% on a spike in volume. Euro Tech Holdings was lately rising 62 cents, or 40.5%, to $2.15. Earlier in the session, the stock touched an intraday high of $2.23, which also represents a new 52-week high. More than 1.3 million shares changed hands in the first two hours of trading Thursday, compared to the stock's 50-day average daily volume of 37,000, according to the Nasdaq. The price and volume moves come in an absence of any company-specific news. However, most Chinese water plays were on the rise as well, including Tri-Tech Holding ( TRIT), which rose nearly 10% to $17.87 on above-average volume, and Duoyuan Global Water ( DGW), which was up 1.8% to $39.46 on heavier-than-usual volume. Euro Tech Holdings has a small 6.4 million-share float, with only 260 shares short as of Sept. 10, according to Yahoo! Finance. More than 50% of the company's shares are held by insiders with another 2% owned by institutions. Some investors were skeptical of Thursday's advance on Internet message boards, arguing that Euro Tech and the other Chinese water plays would see a pullback heading into the weekend. Others argue that Euro Tech could continue to climb with momentum building and few shares sold short. Investors who were very bullish on Euro Tech's prospects called it the "best buy" of the Chinese water plays and will easily top $3 a share and could run up to $5 by the end of the year. Read more about today's high-volume stocks like Vonage in earlier "Pump Up the Volume" posts. -- Written by Robert Holmes in New York.