Air carrier flight crew reported an altitude overshoot due to a light aircraft.

Attributes
ACN	1765880
Time
Date	202010
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 135 Flight Crew Total 14201 Flight Crew Type 135
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 38 Flight Crew Total 12449 Flight Crew Type 2825
Events
Anomaly	Deviation - Altitude Overshoot Deviation - Procedural Clearance

Narrative:

I was the pm. Very light aircraft takeoff weight and fairly quick initial altitude level off - 3;000 feet. I called out of 2 for 3 thousand. Climbing through 2;700 feet; I stated 'watch your altitude we are leveling off at 3;000.' I then called out FMA annunciation of 'speed - VNAV altitude.' first officer immediately began level off. Wasn't aggressive enough in level off. We climbed as high as 3;150 feet and then immediately descended back to 3;000 feet. ATC - ZZZ departure frequency stated; I show you at 3;200 feet and you have traffic at 4;000. At that time we were level at 3;000 and I responded we were level at 3;000.

Original NASA ASRS Text

Title: Air carrier flight crew reported an altitude overshoot due to a light aircraft.

Narrative: I was the PM. Very light aircraft takeoff weight and fairly quick initial altitude level off - 3;000 feet. I called out of 2 for 3 thousand. Climbing through 2;700 feet; I stated 'watch your altitude we are leveling off at 3;000.' I then called out FMA annunciation of 'Speed - VNAV ALT.' FO immediately began level off. Wasn't aggressive enough in level off. We climbed as high as 3;150 feet and then immediately descended back to 3;000 feet. ATC - ZZZ Departure frequency stated; I show you at 3;200 feet and you have traffic at 4;000. At that time we were level at 3;000 and I responded we were level at 3;000.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.