Exchange-traded funds tracking Internet and software stocks were the biggest winners of the week, rising on the back of M&A activity in the software sector. On Friday, BEA Systems ( BEAS) surged 38% after software giant Oracle ( ORCL) made an unsolicited bid for the company. The Internet Infrastructure HOLDRs ( IIH) jumped 12% over the five sessions to $5.85. The First Trust Dow Jones Internet Index ( FDN) added 3.9% to $27.94. The iShares S&P GSTI Software ( IGV) ETF ended up 3.9% at $53.31. ETFs tracking Asia's markets were also among the top winners of the week thanks to big gains overseas. Over the five sessions, Hong Kong's Hang Seng rose 4.6%, and Japan's Nikkei climbed 1.6%. The iShares FTSE/Xinhua China 25 Index ( FXI) advanced 5.5% to $202.20. The SPDR S&P China ( GXC) ETF added 5.2% to close at $103.81. The PowerShares Golden Dragon Halter USX China ( PGJ) gained 3.4% to $35.78. On the other hand, homebuilding and construction-related ETFs were among the worst performers of the week as several builders suffered from an analyst downgrade. Wachovia lowered its 2007 and 2008 earnings estimates for 13 companies in the group, noting escalating cancellation rates and ineffective promotions. Among those cut were Centex ( CTX), Beazer Homes ( BZH), Lennar ( LEN), Toll Brothers ( TOL), Hovnanian ( HOV) and D.R. Horton ( DHI). For the week, the iShares Dow Jones U.S. Home Construction ( ITB) ETF sank 4.7% to $21.72. The SPDR S&P Homebuilders ( XHB) ETF shed 2% to $22.90.