Exchange-traded funds tracking the Internet sector were surging Wednesday on the back of Amazon.com's ( AMZN) blowout quarter.

Following Thursday's close, Amazon easily beat analysts' expectations for the second quarter. After several firms upgraded its stock early Wednesday, Amazon was soaring by 24%.

The Internet HOLDRs ( HHH) was adding $3.31, or 5.6%, to $62.22. The First Trust Dow Jones Internet Index ( FDN) was recently up 61 cents, or 2.4%, to $25.99. The Internet Infrastructure HOLDRs ( IIH) tacked on 7 cents, or 1.3%, to $5.57.

Insurance-related ETFs were also trading higher after both The Chubb Corporation ( CB) and Aflac ( AFL) posted better-than-expected second-quarter earnings. Both Chubb and Aflac shares were jumping by more than 6%.

The KBW Insurance ( KIE) ETF was rising 81 cents, or 1.4%, to $57.12. The iShares Dow Jones U.S. Insurance ( IAK) ETF was adding 68 cents, or 1.3%, to $53.88. The PowerShares Dynamic Insurance ( PIC) ETF was gaining 16 cents, or 0.9%, to $18.03.

Elsewhere, biotech ETFs were celebrating a 16% jump in shares of Alexion Pharmaceuticals ( ALXN), which narrowed its second-quarter loss compared to a year ago and came in ahead of Wall Street's expectations.

The First Trust Amex Biotechnology Index ( FBT) was climbing 40 cents, or 1.7%, to $24.47. The SPDR S&P Biotech ( XBI) was higher by 54 cents, or 1.1%, to $52.04.

The iShares Dow Jones U.S. Aerospace & Defense ( ITA) ETF was also gaining ground after holding General Dynamics ( GD) beat estimates with its quarterly earnings report. General Dynamics was recently up almost 3%, and the ETF was adding 64 cents, or 1%, to $65.97.

Basic materials-related bundled securities were among the biggest losers of the session. Among individual stocks, U.S. Steel ( X), Nucor ( NUE), DuPont ( DD), Consol Energy ( CNX) and Arch Coal ( ACI) slumped 2% or more.

The Ultra Basic Materials ProShares ( UYM) ETF dropped $2.78, or 3%, to $91.48. The Materials Select Sector SPDR ( XLB) was losing 94 cents, or 2.2%, to $40.96. The iShares Dow Jones U.S. Basic Materials ( IYM) ETF was down $1.47, or 2%, to $71.02. The Vanguard Materials ( VAW) ETF was shedding $1.62, or 1.9%, to $85.41.