The market took a step back and caught its breath after the close on Friday. Volume remained extremely light following a busy, back-and-forth week filled with earnings reports from some of the world's largest companies.

The top volume mover on Instinet was SurModics ( SRDX - Get Report), a maker of coatings for medical devices. SurModics remained unchanged during trading in the extended session. The company closed the regular session down 6.2%, to $48.80. On Tuesday the company announced earnings that were in line with analysts' projections.

Spanish telephone company Telefonica ( TEF - Get Report), was also unchanged at $35.60, and was one of the top movers, despite light trading. Friday the company agreed to lend financial support to Argentina.

A number of tech names that reported earnings this week were among the leading movers on Instinet and Island ECN. Microsoft ( MSFT), which reported earnings inline with the Street's estimates on Thursday fell 0.1%, to $69.11 on Instinet, but gained 0.03% on Island. IBM ( IBM - Get Report) also made the list of most actively traded stocks in the after-hours market two days after reporting earnings that were in line with Wall Street's projections. IBM share remained unchanged at $105.70. Intel ( INTC - Get Report) was up 0.3%, to $30.01. The chipmaker said on Tuesday that its earnings were in sync with analysts' predictions and that it increasingly confident that a microprocessor recovery will happen in the third and fourth quarters.

For the rest of the market it was a mixed bag of low hills and small valleys in the early going before the majority of the companies slipped into negative territory. No stock was moving significantly either way initially and volume remained light -- no surprise for a Friday night in the summer when no major earnings releases are scheduled. However, the typical tech names were reluctant to let a busy week full of earnings reports come to an end. JDS Uniphase ( JDSU) was down 0.3%, to $9.90, while Dell fell 0.3%, to $27.82. Cisco Systems was up 0.2%, to $18.03.

10 most active stocks on Island ECN (5:40 p.m. EDT)
Company Price Change Session Volume
Nasdaq 100 Tracking Stock (QQQ) 41.80 N/A 224,208
Exodus Communications (EXDS) 1.09 +0.01 196,308
Komag (KMAG) 0.13 +0.01 139,591
Aastrom Biosciences (ASTM) 2.26 +0.22 76,010
Metromedia Fiber Networks (MFNX) 1.22 -0.01 74,609
Microsoft (MSFT) 69.20 +0.02 66,052
StemCells (STEM) 6.94 +0.64 57,643
Sun Microsystems (SUNW) 15.04 +0.01 40,582
Tripath Technology (TRPH) 1.80 -0.06 35,819
iBeam Broadcasting (IBEM) 0.25 -0.001 33,565

Island ECN offers trading, mainly in Nasdaq-listed stocks, from 7 a.m. to 8 p.m. EST.

Confused? TheStreet.com explains how the rules change when the sun goes down in Investing Basics: Night Owl, a section devoted to after-hours trading.