It wasn't more than a year ago that commercial real estate investors found a quiet and underpublicized sector they could buy into with little risk and little churn. But today, quiet is not an adjective for the self-storage investment market. A combination of huge transactions and dropping rent prices in the sector have upended what was considered an easy and tranquil alternative investment to troubled office space and multifamily housing. This month, the sector's fireworks reached maximum visibi