Support and resistance is a concept in technical analysis that the movement of the price of a security will tend to stop and reverse at certain predetermined price levels. A support level is a price level where the price tends to find support as it is going down. This means the price is more likely to bounce off this level rather than break through it. However, once the price has passed this level, even by a small amount, it is likely to continue dropping until it finds another support level.

A resistance level is the opposite of a support level. It is where the price tends to find resistance as it is going up. This means the price is more likely to bounce off this level rather than break through it. However, once the price has passed this level, even by a small amount, it is likely that it will continue rising until it finds another resistance level.

A security is a fungible, negotiable instrument representing financial value. Securities are broadly categorized into debt securities (such as banknotes, bonds and debentures), and equity securities, e.g., common stocks. The company or other entity issuing the security is called the issuer. What specifically qualifies as a security is dependent on the regulatory structure in a country. For example private investment pools may have some features of securities, but they may not be registered or regulated as such if they meet various restrictions.

Securities may be represented by a certificate or, more typically, by an electronic book entry. Certificates may be bearer, meaning they entitle the holder to rights under the security merely by holding the security, or registered, meaning they entitle the holder to rights only if he or she appears on a security register maintained by the issuer or an intermediary. They include shares of corporate stock or mutual funds, bonds issued by corporations or governmental agencies, stock options or other options, limited partnership units, and various other formal investment instruments that are negotiable and fungible.

Technical analysis is frequently contrasted with fundamental analysis, the study of economic factors that some analysts say can influence prices in financial markets. Technical analysis holds that prices already reflect all such influences before investors are aware of them, hence the study of price action alone. Some traders use technical or fundamental analysis exclusively, while others use both types to make trading decisions.

However, there are also many stock traders who proclaim technical analysis not as a science for predicting the future but instead as a valuable tool to identify favorable trading opportunities and trends. The assumption is that all of the fundamental information and current market opinions are already reflected in the current price and when viewed in conjunction with past prices often reveals recurring price and volume patterns that provide clues to potential future price movement.

Pivot point calculations are used by security traders to attempt to predict support and resistance levels. They are commonly used in the forex and commodity futures markets. Pivot point analysis is a subset of technical analysis, although it is not as popular or well known as other technical methods.

Pivot points are frequently used by foreign exchange traders as a means to calculate resistance and support levels which are, in turn, used as visual cues to execute trades. Pivot point calculations provide traders with objective visual bench marks which some use to predict price changes, although the validity of these levels is still subject to debate.

Support and resistance levels can be identified by trend lines. Some traders believe in using pivot point calculations. The more often a support/resistance level is tested (touched and bounced off by price), the more significance given to that specific level. If a price breaks past a support level, that support level often becomes a new resistance level. The opposite is true as well, if price breaks a resistance level, it will often find support at that level in the future.

A trend line is a bounding line for the price movement of a security. A support trend line is formed when a securities price decreases and then rebounds at a pivot point that aligns with at least two previous support pivot points. Similarly a resistance trend line is formed when a securities price increases and then rebounds at a pivot point that aligns with at least two previous resistance pivot points. The following chart provides an example of support and resistance trend lines.