It is a matter of timing, depending on the market.
It depends on both the timing and the market, as well as the type of business you want to start and the business model.
There is a cycle to the stock market... It is up for a few years, and then it is down for a while. When it goes up, there is a tendency to try to raise a lot of capital in order to take advantage of the boom, which causes a bubble to form, and when it bursts, everyone looses. This happened before the NASDAQ crash in 2000, and before the financial crises we are currently in.
If you want to succeed, you need to go against these trends, and be conservative when money is cheap and expend using that cheap money when everyone else is down. Many great companies started during recessions when competition was scarce.
VCs have a clause in their term-sheets that protects them from future round in lower valuations, which means that if you are raising money in the boom years, and you waste it all away on rapid expansion, you will loose everything during the next round of financing. This can be seen in the documentary startup.com (http://www.imdb.com/title/tt0256408/).
You need to consider your business model, and see which approach makes more sense. Some businesses can only work if you bootstrap, others only if you raise serious money. In some cases there is a choice to be made, and in many many cases, the business model doesn't work regardless of how you fund it, and it is time to move on to the next big idea.