The simple index fund solution has been adopted as a cornerstone of investment strategy for many of the nation's pension plans operated by our giant corporations and state and local governments. Indexing is also the predominant strategy for the largest of them all, the retirement plan for federal government employees, the Federal Thrift Savings Plan (TSP). The plan has been a remarkable success, and now holds some $173 billion of assets for the benefit of our public servants and members of armed services.