feat: add peg, chaser, and trailing-stop order types

AGENTS.md

@@ -289,6 +289,30 @@ bitmex order buy  XBTUSD 100 --price 50000 --strategy Long --yes -o json
 bitmex order sell XBTUSD 100 --price 52000 --strategy Short --yes -o json
 ```
 
+### Peg, Chaser & Trailing Stop orders
+
+Pegged orders price relative to the live market instead of a fixed price. The primitive
+`--peg-price-type`/`--peg-offset-value` flags on `buy`/`sell` map straight to the API
+`pegPriceType`/`pegOffsetValue` fields; `chase` and `trailing-stop` are guided wrappers that
+set `ordType`/`execInst` and **reject a wrong-sign offset locally** (category `validation`)
+before it reaches the exchange.
+
+```bash
+# Pegged limit — requires exec_inst Fixed. PrimaryPeg = near touch, MarketPeg = far touch.
+bitmex order buy XBTUSD 100 --order-type Pegged --exec-inst Fixed \
+    --peg-price-type PrimaryPeg --peg-offset-value -1 --yes -o json
+
+# Chaser (ordType Pegged) — follows the top of book. Sign rule: Buy offset <= 0, Sell >= 0.
+# Max 5 chaser orders per account. --bothways keeps a constant distance (ChaserBothways).
+bitmex order chase XBTUSD Buy  100 --offset -1 --yes -o json
+bitmex order chase XBTUSD Sell 100 --offset  1 --bothways --yes -o json
+
+# Trailing stop (pegPriceType TrailingStopPeg) — sign rule is the OPPOSITE of chaser:
+# Sell offset <= 0, Buy offset >= 0. --limit-price promotes Stop to StopLimit.
+bitmex order trailing-stop XBTUSD Sell 100 --offset -100 --yes -o json
+bitmex order trailing-stop XBTUSD Sell 100 --offset -100 --limit-price 49000 --yes -o json
+```
+
 ### Tick size and lot size alignment
 
 Every instrument enforces a minimum price increment (`tickSize`) and minimum quantity increment (`lotSize`). Submitting a price or quantity that isn't a multiple of these will return a `400 Invalid price` or `400 Invalid quantity` error.

CLAUDE.md

@@ -106,6 +106,25 @@ bitmex order buy XBTUSD 100 --price 50000 --validate -o json
 bitmex order buy XBTUSD 100 --price 50000 --yes -o json
 ```
 
+### Peg, chaser & trailing-stop orders (auth required, dangerous)
+
+Pegged orders price relative to the live market. `chase` and `trailing-stop` are guided
+wrappers that set `ordType`/`execInst` and enforce the offset sign locally (a wrong sign
+returns a `validation` error before reaching the exchange). Their sign rules are opposite:
+
+```bash
+# Pegged limit — requires exec_inst Fixed (PrimaryPeg = near touch, MarketPeg = far touch)
+bitmex order buy XBTUSD 100 --order-type Pegged --exec-inst Fixed \
+  --peg-price-type PrimaryPeg --peg-offset-value -1 --yes -o json
+
+# Chaser — follows the top of book. Buy offset <= 0, Sell offset >= 0. Max 5 per account.
+bitmex order chase XBTUSD Buy 100 --offset -1 --yes -o json
+bitmex order chase XBTUSD Sell 100 --offset 1 --bothways --yes -o json
+
+# Trailing stop — Sell offset <= 0, Buy offset >= 0 (opposite of chaser)
+bitmex order trailing-stop XBTUSD Sell 100 --offset -100 --yes -o json
+```
+
 ### Testnet
 
 ```bash

CONTEXT.md

@@ -193,6 +193,13 @@ bitmex order close XBTUSD --side sell --tp-px 60000 --trigger last --yes -o json
 bitmex order close XBTUSD --side sell --stop-px 50000 --tp-px 60000 --trigger mark --yes -o json  # OCO bracket (fill one cancels the other)
 bitmex order close XBTUSD --side sell --yes -o json                                           # market close 100%
 
+# Peg / Chaser / Trailing Stop (offset sign is enforced client-side)
+bitmex order buy XBTUSD 100 --order-type Pegged --exec-inst Fixed \
+    --peg-price-type PrimaryPeg --peg-offset-value -1 --yes -o json  # pegged limit
+bitmex order chase XBTUSD Buy 100 --offset -1 --yes -o json          # chaser: Buy <= 0, Sell >= 0
+bitmex order chase XBTUSD Sell 100 --offset 1 --bothways --yes -o json
+bitmex order trailing-stop XBTUSD Sell 100 --offset -100 --yes -o json  # trailing: Sell <= 0, Buy >= 0
+
 # Positions
 bitmex position list -o json
 bitmex position leverage XBTUSD 10 -o json

README.md

@@ -189,6 +189,30 @@ bitmex order close XBTUSD --side sell --stop-px 50000 --tp-px 60000 --trigger ma
 bitmex order close XBTUSD --side sell                                  # market close 100%
 ```
 
+Pegged orders price relative to the live market. `chase` and `trailing-stop` are guided
+wrappers that set the right `ordType`/`execInst` and enforce the offset **sign rule**
+locally (a wrong sign is rejected before it reaches the exchange).
+
+```bash
+# Pegged limit — Fixed price relative to the touch (PrimaryPeg = near, MarketPeg = far)
+bitmex order buy XBTUSD 100 --order-type Pegged --exec-inst Fixed \
+    --peg-price-type PrimaryPeg --peg-offset-value -1
+
+# Chaser — re-prices to follow the top of book. Buy offset <= 0, Sell offset >= 0.
+bitmex order chase XBTUSD Buy  100 --offset -1              # ChaserClassic (default)
+bitmex order chase XBTUSD Sell 100 --offset  1 --bothways  # ChaserBothways
+
+# Trailing stop — stopPx trails the market. Sell offset <= 0, Buy offset >= 0.
+bitmex order trailing-stop XBTUSD Sell 100 --offset -100                     # Stop
+bitmex order trailing-stop XBTUSD Sell 100 --offset -100 --limit-price 49000 # StopLimit
+
+# Amend a live peg's offset without cancel/replace
+bitmex order amend --order-id <id> --peg-offset-value -2
+```
+
+See [Order Types & Execution Instructions](https://support.bitmex.com/hc/en-gb/articles/6911327963293)
+for the full peg/chaser reference.
+
 ### Positions (auth required)
 
 ```bash