A spike is a comparatively large upward or downward movement of a price in a short period of time. (investopedia.com)
Today, crossed the $ 10,000 mark after about 2 weeks of downward movement in both its price and the general market capitalization. (crypto-lines.com)
Also we can draw a flag pattern which is a continuation chart pattern and it tells us about further downward movement, if the price breaks the signal line. (hacked.com)