"Goldbug" is also a term used for investors who are investing in gold, often to the disbelief and ridicule of the perpetual stock market bulls. To be a goldbug, you have to invest in gold. You do this by either buying physical gold (gold bars, gold coins, gold jewellery, etc), buying shares in gold mining companies or buying gold in the futures market (futures or options).
It has also been suggested that being a goldbug also means that you have to believe that the current monetary system we have today - fiat money - is flawed and doomed to disaster sometime in the future.