It can go down if a crisis like 2008 repeatsbut then,Gold went down because it was a deflationary crisis, a credit crunch. Banks, businesses and people were scrambling for liquidity and would sell anything to be more liquid. After the credit crunch the FED launched QE and gold rose accordingly.
I would argue though, that because the gold market is more leveraged bitcoin would suffer less from a deflationary collapse. The paper gold market is huge.
One crisis isn't like the other. Maybe we're going to have a Greek/Cyprus like crisis, where governments orchestrate bail-ins. This is very bullish for bitcoin, but it will be hard to buy bitcoins when your bank account is frozen.
Or maybe inflation picks up and people start to lose confidence in their national currencies. This is very bullish for bitcoin.