Monday, 12/22/14; approx. 12:40pI had met some friends for lunch at a restaurant in the Alviso area of San Jose, CA on Monday, December 22, 2014. I was returning to work and I exited eastbound Hwy. 237 at McCarthy Blvd. in Milpitas. As I approached the traffic signal at the intersection of the frontage road at McCarthy Blvd., looking eastward toward the mountains I noticed what appeared to be 5-6 metallic spheres hovering above the foothills, swaying slightly back and forth over the cityscape. They appeared to be moving in unison, not breaking their formation. Puzzled and surprised, I pulled out my iPhone and began videoing what I thought were the spheres. After a few seconds, I zoomed my phone in to get what I hoped would be a better shot. I was only able to remain stopped at the intersection for a few moments, then the light changed to green and traffic began moving, so I stopped recording and drove back to the office.Eager to view what I thought I had just videoed, I pulled into a parking space at my office and replayed the video. I was initially greatly disappointed as the video didn't show any signs of the spheres. Maybe I was filming in the wrong area - I had hurriedly pulled out my phone and was only able to be at the intersection for a few moments. For some reason, the video also initially played for the entire length in slow motion. I watched it a couple of times and was about to give up hope, thinking maybe what I saw hadn't actually been there, when I noticed a moving object in the video - just not one I had seen as I was filming. The black object starts off diagonally above the traffic signal and to the left, moves down below the level of the signal, then moves up and to the right just above the signal, shoots diagonally to just the top of the street light nearest to the traffic signal, then back down about mid-way between the streetlight and traffic signal. The object then begins a straight ascent upward toward the top of the cloud bank, disappearing through the clouds momentarily, then re-appearing about 2/3 of the way to top of the clouds on the right hand side of the picture. It stops there briefly and then makes a rapid diagonal leftward descent, partially through the clouds, back to near its original position in the video. It then makes another rapid diagonal rightward ascent back up into the clouds, appearing again near the top of the cloud bank, only to make another fast diagonal descent back through the clouds. Unfortunately, this is the point where I zoom the video in to the metallic spheres I was seeing. The object is briefly seen in larger detail before the zoom takes it out of the picture altogether - it does not appear again during the rest of the slow motion video.This object wasn't the reason I had made the video, and didn't see it at all when I initially filmed. At first I thought the object might have been a bird. It was only later, when the video starting playing at its normal speed did I realize how fast this occurred. I don't think it could be a bird with the speed of the object; and way it moves in and out of the clouds seems to indicate some distance. For this same reason I don't think it could be an insect. Also, the entire length of time of the object is seen in the video is only around 5-6 seconds in real time.This incident followed another very strange experience that happened to me approximately 3 weeks earlier in southeast Texas that I will report separately in the database. I have video that I took of the 12/22/14 sighting on my iPhone that I converted to MOV format, both in slow motion and regular speed. Unfortunately, both videos play sideways. I'm happy to share this with MUFON for viewing/investigation purposes but I am uncomfortable with the exclusive license wording on the license to show/rebroadcast it as well as it wording on the website indicating that video attached to the report is viewable by the public.