The value of Thrift Savings Plan funds has been volatile over the past year, reaching new highs and producing some big dips. These market fluctuations can make investors nervous. This is doubly true if this is your first experience with sharp swings in the value of your investments. Here's how some of the recent turbulence played out in the TSP's individual funds most susceptible to market fluctuations -- the C, S and I Funds, also known as the Stock Funds: While recording some of the steepest