Cisco Systems (CSCO) is slated to report its Q1 results after hours  tonight, and analysts polled by Thomson Financial are expecting the company to report a profit of $0.39 per share on revenue of $10.29 billion.

The stock demonstrates a long-term pattern of extending session-to-session performance on earnings announcements, adding to gains or losses from the after-hours to the next day.

Looking deeper into the performance data, shorts should be interested to know that CSCO has seen a negative post-bell earnings-driven trade in 12 of the 21 quarters we've tracked, and in nine of those downside evening moves the stock has followed that trade with a more aggressive negative run in the next day's regular session.

On the long side, CSCO is about evenly mixed, recording nine earnings-driven upside evening moves in the 21 quarters we've followed - widening those gains four times the next day and recording five other events where the gains were cut back or reversed the following day.

The safe play here is on the short side should CSCO sell off following the earnings release after the bell.

For those wanting to dig into the historical earnings event reaction data, take a look back at how CSCO has reacted to earnings both after-hours and the following regular session going back five years below.

On Aug. 5, 2008, CSCO advanced 6.1% in after-hours trade after beating Q4 expectations and reaffirming its growth guidance. It saw that gain narrow the next day, closing the Aug. 6 regular session up 5.6%.

On May 6, 2008, CSCO gained 1.3% in evening trade after topping Q3 Street estimates and setting revenue guidance in a range that straddled expectations. The stock lost its gain the following day, ending the May 7 regular session down 2%.

On Feb. 6, 2008, the stock fell 7.5% during evening trading after CSCO largely meets with Q2 results, but its revenue guidance disappoints. Shares rebounded to close up 1.3% the next day.

On Nov. 7, 2007, CSCO plummeted 9.6% in after-hours trade after topping estimates but also guiding its Q2 revenue view just below the Street view. It narrowed its negative move slightly the following day, closing the Nov. 8 regular session down 9.5%.

On Aug. 7, 2007, CSCO rose 5.7% in night trade after topping Q4 estimates and guiding Q1 sales above Street views. Shares added a bit more the next day to end the regular session up 6.7%.

On May 8, 2007, CSCO slid 5.3% in after-hours trade after the company beat expectations and guided mostly in line for its Q4. It headed slightly lower the following day, losing 6.5% by the closing bell.

On Feb. 6, 2007, shares gained 4.5% in the evening hours after the company reported a strong year-over-year gain in revenue but offered an outlook that straddled the Street view. The gain was trimmed to 2.9% the next day.

On Nov. 8, 2006, CSCO gained 7.3% in night trade after topping Q1 estimates and forecasting Q2 sales up 24-25% from a year ago. However, shares gave back some of those gains, closing the next day session up 6.4%.

On Aug. 8, 2006, CSCO surged 9.5% in after-hours trade after the company topped Q4 expectations and set a strong revenue growth outlook. The stock added to its upside in the Aug. 9 regular session, closing the day up 14.3%.

On May 9, 2006, shares fell 1.2% in the evening session after a cautious revenue outlook on the evening conference call trumped quarterly results ahead of the Street’s view. Shares fell 4.2% the next day.

On February 7, 2006, CSCO gained 5.5% after meeting Q2 sales estimates and topping EPS by a penny. The shares strengthened further the next day, ending the regular session up 7.2%.

On November 9, 2005, CSCO eased 2.2% in night trade despite beating earnings expectations by a penny per share. The shares widened their losses the next day, closing regular trading down 3.3%.

On August 9, 2005, CSCO fell 3.4% in evening trade after topping Q2 revenue estimates and matching on EPS. It widened that loss in the August 10 regular session, sliding 6.9%.

On May 10, 2005 CSCO edged up 0.2% in after-hours trade after the company topped Street expectations and guided its sales view in-line to higher than estimates. It added to its upside on May 11, rising 1.8% between the bells.

On Feb. 8, 2005 CSCO slipped 1.5% in night trade after the company reported in-line Q2 results but set its Q3 view to match or come in slightly below estimates. It saw more aggressive downside momentum on Feb. 9, losing 3.3% by the closing bell.

CSCO lost 2.5% the night of Nov. 9, 2004 after reporting Q1 results matching the Street view, but issuing Q2 sales shy of current expectations. The stock outpaced its evening decline in the next day's regular session, dropping a more aggressive 6.6%.

CSCO declined 5% the night of Aug. 10, 2004 after the company beat estimates but offered weak guidance. The stock added to its downside on Aug. 11, tumbling 10.6% by the closing bell.

CSCO slid 2.2% the night of May 11, 2004 after the company reported better-than-expected Q3 results and guided its Q4 revenue modestly above the Street view. The stock closed the next day's regular session with a narrower decline, down 1.3%.

Back on Feb. 3, 2004 CSCO closed the after-hours down 4.5% after the company beat Q2 expectations, but noted it only expects Q3 revenue up 1% to 3% over Q2. The stock closed the Feb. 4 regular session with a more aggressive 8.8% decline.

On Nov. 5, 2003, CSCO closed the after-hours session with a 5.8% advance after the company reported Q1 results well ahead of the consensus. The stock hit an intra-day high of plus 6.1% on Nov. 6, but couldn't sustain the more aggressive gains it recorded in the previous night's session. It ended the Nov. 6 regular session with a more modest 5% rise.

On Aug. 5, 2003, CSCO closed after-hours trade down 5.1% after the company reported Q4 results in line with expectations but posted disappointing Q1 guidance. The stock closed the Aug. 6 regular session with a 6.4% decline.

Lots of other good trading opportunities likely to emerge in late trading tonight. Stay tuned to after hours stock news and play these short term opportunities while the broad market continues to gyrate.