> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trinigence.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Crossovers & Trend Changes
> How crossover events and trend state changes work in Trinigence strategies.
## Events vs states
One of the most common sources of confusion in strategy logic is the difference between:
* **events** (something happens now)
* **states** (something is true over time)
Crossovers and trend changes are **events**.
They trigger at a specific moment - not continuously.
***
## What a crossover is
A **crossover** occurs when one value moves from one side of another value to the other.
Examples:
```text theme={null}
EMA(20) crosses above EMA(50)
MACD line crosses below signal
RSI(14) crosses above 50
```
A crossover:
* triggers on the candle where the crossing happens
* is true for one evaluation only
* becomes false again on the next candle
***
## Crossovers vs comparisons
Compare:
**Crossover**
```text theme={null}
EMA(20) crosses above EMA(50)
```
Triggers once.
**Comparison**
```text theme={null}
EMA(20) > EMA(50)
```
Remains true as long as the condition holds.
Most entries should be based on crossovers, not comparisons.
***
## What a trend change is
A **trend change** is a transition from one directional state to another.
Examples:
```text theme={null}
Trend changes to bullish
Supertrend flips to buy
Trend direction switches to down
```
Trend changes:
* are event-based
* usually derived from trend indicators
* often abstract multiple internal calculations
***
## Trend state vs trend change
**Trend state**
```text theme={null}
Trend is bullish
```
**Trend change**
```text theme={null}
Trend changes to bullish
```
Trend states persist.\
Trend changes trigger once.
***
## Common uses
### Entries
Crossovers and trend changes are most commonly used for:
* trade entries
* initial position opening
* momentum confirmation
Example:
```text theme={null}
Go long when EMA(20) crosses above EMA(50).
```
***
### Exits
They can also be used for exits.
Example:
```text theme={null}
Exit long when trend changes to bearish.
```
***
## Evaluation timing
Crossovers and trend changes are evaluated:
* on candle close
* on the strategy timeframe
* once per candle
If the cross happens intrabar but is gone at close, it does not trigger.
There is no intrabar crossover detection by default.
***
## Direction-specific behavior
Crossovers may be defined per direction.
Example:
```text theme={null}
Go long when EMA(20) crosses above EMA(50).
Go short when EMA(20) crosses below EMA(50).
```
Each event is evaluated independently.
***
## Defaults and assumptions
If a crossover or trend change is:
* clearly stated → used exactly
* implied → ATI infers conservatively
* ambiguous → ATI requests clarification
See how event logic is inferred.
***
## Common mistakes
Crossovers are events, not states. Use comparisons for filters.
A crossover fires once, not continuously.
Trend changes are moments. Trend states persist.
***
## Best practices
* Use crossovers for entries
* Use states for filters
* Do not chain multiple crossovers unnecessarily
* Validate trigger points visually
Learn how crossovers fit into logic.
***
## What to read next
Trend, momentum, volatility indicators.
How events open trades.
How events close trades.
Return to the big picture.
Events trigger action.\
States define context.