But before you dive in, educate yourself. New Investor? Investing in yourself is one of the best possible investments you can make. On top of this, a broker may take as much as a 6 percent cut off the top of the sales price as a commission. The funds invest in debt instruments such as T-bills, T-notes, T-bonds and mortgage-backed securities issued by government-sponsored enterprises such as Fannie Mae and Freddie Mac. An industry-specific index fund is typically an ETF, and some of these have low expense ratios, meaning the ongoing cost of the fund is reasonable. Would be nice.