The Dow Jones Industrial average continued its losing streak Friday, dropping another 200 points to close the week 585 points lower.  Global markets remained generally volatile after the index of 30 of the biggest publicly traded American companies fell more than 300 points Thursday.  For investors, it has been a rollercoaster week of ups and downs.

Just last week, investors were reveling in a bull market as the Dow sailed into record territory.  But it didn't take long for the market to shift.  Concerns over the continuing decline in sales of new and existing homes along with a tight lending market forced many investors to cut their losses.

Sam Stovall, chief investment strategist at Standard and Poor's says the housing market could remain weak until the middle of next year. "Basically our feeling is that the bottom is not likely to be seen for the next several quarters.  So with that, I think what we're seeing are those investors who came in a little too early bailing out of their positions and that's helping to drag down the rest of the market."

In Asia, Tokyo's Nissei Index fell more than two percent Friday, while Hong Kong's Hang Seng plummeted 640 points to close three percent lower.

Richard Hunter with UK Equities at Hargreaves Lansdown says uncertainty is driving the volatility. "If there's one thing the market doesn't like it's uncertainty.  Even if there's bad news that's something that can be factored in."

Fueling the uncertainty is the price of oil, which remains near record highs. But financial analysts say there is an upside.

Mellody Hobson says right now more than 7,800 companies are trading at 52-week lows. "That means they're at a bargain price versus this time last year, which means there's an upside there as opposed to more downside and I think that's a good thing."

Equity strategist Henk Potts believes the Dow's drop is just a minor blip. "The reality is global growth remains very strong, corporate profitability still remains very strong, so the fundamentals still look good.  Listen, stock markets are volatile.  We know that.  That's why it's all about investing in the long term."

Putting things into perspective, this week's market decline represents about a three percent loss.  Experts say that's almost insignificant compared to the 23 percent drop the markets suffered on Black Monday in 1987.