SAN FRANCISCO—Frantic might be the word to accurately describe the market’s critical supply/demand imbalance as of today. The total square footage of tenants seeking space in the market rose to 7.1 million square feet during the first quarter, surpassing the level of existing available supply by nearly 300,000 square feet, according to CBRE research.

Supply is especially limited for large blocks of 100,000-plus square feet. There are currently two such blocks available, but there are a mere 22 tenants in the market for this type of space, says CBRE.