A market trend is a tendency of financial markets to move in a particular direction over time.[dead link] These trends are classified as secular for long time frames, primary for medium time frames, and secondary for short time frames. Traders identify market trends using technical analysis, a framework which characterizes market trends as predictable price tendencies within the market when price reaches support and resistance levels, varying over time.Strictly, a trend can only be determined in hindsight, since at any time prices in the future are not known. This does not prevent people from prognosticating about future trends. Some people ascribe trends to pareidolia.[citation needed]The terms bull market and bear market describe upward and downward market trends, respectively, and can be used to describe either the market as a whole or specific sectors and securities.