ROUNDING ERROR — When numbers are rounded many times. errors creep into the result. For
example, 2.4+8.4=5.8 which rounds to 6, but if we round 2.4 and 3.4 we get 2+3=5.
TREND—A straight line pattern to prices. This may be clouded by price variations above and below the
AUTOREGRESSIVE—One today in terms of past days. The atuoregressive part of an ARIMA model
uses previous days prices to predict today's price. The "previous days" could be just yesterday, or
yesterday and the day before yesterday etc.