(Reuters) - Get ready for a long and ugly ride.

The Nasdaq logo is etched into glass at the headquarters for the Nasdaq in New York March 3, 2015. REUTERS/Lucas Jackson

On Friday, the Nasdaq Composite .IXIC closed almost 22 percent below its record high daily close on Aug. 29, signaling a nearly nine-and-a-half year bull market run for the index ended in late summer.

That cumulative loss indicates Nasdaq is now in a bear market, typically defined as a decline of 20 percent or more from a 52-week or longer high close.

Nasdaq has endured 10 previous bear markets since it was launched in February 1971. Six of them lasted a year or longer. In three of them the index lost more than half its value.

If this one bears any resemblance to its predecessors, investors should expect another eight to nine months of declines and their losses to deepen significantly from here.

(Graphic: Past Nasdaq bear markets - tmsnrt.rs/2SgqhtU)

Some key facts of past Nasdaq bear markets:

* On average, they have featured a decline of 39.74 percent over 248 trading days, roughly the length of a calendar year.

* The median decline has been 32.25 percent over 266 trading days.

* The great dot-com bust of the early part of the century still stands as the index’s biggest and longest-lasting collapse. Nasdaq lost a gut-wrenching 77.93 percent over 674 trading days between March 2000 and October 2002.

* The most mild bear market saw a decline of 20.37 percent over 44 days between Sept. 13, 1978, and Nov. 14, 1978.

* The shortest one lasted just 34 days from Feb. 8, 1980, to March 27, 1980. The index fell 24.91 percent in that span.

* Over its nearly 48 years in existence, Nasdaq has spent roughly 20 percent of the time - more than 2,500 trading days - in bear market territory.

(For an interactive graphic, please click: tmsnrt.rs/2RaJ3FD)