All rights reserved. Like other Vanguard funds, this one is quite inexpensive, charging just 7 basis points annually. Short-term bonds generally mature within one to five years, and yields are lower than those of their longer-term cousins. Personal Finance. Following this theory, a portfolio containing a variety of assets poses less risk and ultimately yields higher returns than one holding just a few. Many fund managers are given the flexibility to include certain other assets to help diversify their investments even further.