I am a pilot who noticed what appeared to be a craft flying from the south heading north. it looked to short to be an airliner and to round and featureless to be a small airplane. the sun was just coming up over the mountains and the object was to my west. it was highly reflective. so i went outside to get a better look. then as i had access to the entire sky i looked up and began to count numerous highly reflective objects in the sky all hovering in place. when i looked again for the object that was moving, it either had disappeared or stopped. there was an object roughly in the area where i had lost sight of it when i looked up at the others. that lower object was closer and remained for a much longer period. it is possible they were balloons. but all 13 or perhaps more that i counted were all at different altitudes and not one of them was drifting. higher clouds moved in over their location, so the upper winds were active it is hard to judge the altitudes not knowing their actual size and they were over the bay a little more than a mile away. somewhere between 2 and 4 thousand feet when i first saw them. there were a few that seemed to fade in and out a few times. but being at a distance and with other white clouds near by i could not be sure it was not my eyes re-focusing on them that made them appear after looking away for a minute. i did shot a video on my iphone 6s. but unless someone has sophisticated editing software, the brightness of the sun on the clouds seems to have prohibited the camera from capturing the objects. my wife was also witness to what i saw and counted the same number of objects as i did. i observed the object for 30 minutes until they became smaller and smaller and disappeared. it appeared as if they were ascending but never any lateral movement. i am happy to be wrong and shown that these were only balloons acting in an unusual manner. but until i can discover there was zero wind up to at least 4000 feet that morning, i have to conclude that these objects warrant further investigation.