noun
sudden fall in stock prices; stock market crash
Used in stock market contexts to describe a sharp, sudden drop in prices.
今日のがら落ちで多くの投資家が損失を出した。
Many investors suffered losses due to today's sudden stock price drop.
Compound of がら (onomatopoeic for crashing down) and 落ち (fall). The exact derivation is uncertain; the kanji 瓦落 is ateji.