vincentf13 · google-labs-jules · Dec 16, 2025
diff --git a/design/exchange/0.exchange_design.md b/design/exchange/0.exchange_design.md
@@ -2661,7 +2661,7 @@ Positions 服務必須在啟動時預熱所有交易對的靜態配置與風控
 | ---------- | ------------------------------ | -------------------- | --------------------------------------------------------------------------------------------------------------------- |
 | 待處理器flip情況 | `account.trade-margin-settled` | `TradeMarginSettled` | **開倉入帳**：建立新倉位或增加持倉。更新 `margin` (從錢包轉入) 與 `entry_price`。                                                              |
 |            | `matching.trade-executed`      | `TradeExecuted`      | **平倉結算**：僅處理 `makerIntent/takerIntent = REDUCE/CLOSE` 的成交；減少持倉、釋放凍結數量、計算 `realized_pnl` 並發布 `PositionMarginReleased`。 |
-|            | `market.mark-price`            | `MarkPriceUpdated`   | **行情更新**：使用最新標記價格重算 `unrealized_pnl` 與 `liquidation_price`。若觸發強平線則發布 Alert。                                           |
+|            | `market.mark-price`            | `MarkPriceUpdated`   | **行情更新**：使用最新標記價格重算 `unrealized_pnl` 與 `liquidation_price` 並發布 `PositionUpdated` (若有顯著變動)。(注意：強平觸發由 Risk 服務負責)  |
 
 ---
 

diff --git a/service/exchange/exchange-position/pom.xml b/service/exchange/exchange-position/pom.xml
@@ -69,5 +69,9 @@
             <groupId>open.vincentf13</groupId>
             <artifactId>exchange-matching-sdk-mq</artifactId>
         </dependency>
+        <dependency>
+            <groupId>open.vincentf13</groupId>
+            <artifactId>exchange-market-sdk-mq</artifactId>
+        </dependency>
     </dependencies>
 </project>
diff --git a/...-position/src/main/java/open/vincentf13/exchange/position/domain/model/PositionEvent.java b/...-position/src/main/java/open/vincentf13/exchange/position/domain/model/PositionEvent.java
@@ -118,4 +118,41 @@ public static PositionEvent createTradeEvent(Long positionId,
                 .occurredAt(occurredAt)
                 .build();
     }
+
+    public static PositionEvent createMarkPriceEvent(Long positionId,
+                                                     Long userId,
+                                                     Long instrumentId,
+                                                     BigDecimal newQuantity,
+                                                     BigDecimal newReservedQuantity,
+                                                     BigDecimal newEntryPrice,
+                                                     Integer newLeverage,
+                                                     BigDecimal newMargin,
+                                                     BigDecimal newUnrealizedPnl,
+                                                     BigDecimal marginRatio,
+                                                     BigDecimal newLiquidationPrice,
+                                                     Long tradeId,
+                                                     Instant occurredAt) {
+        return PositionEvent.builder()
+                .positionId(positionId)
+                .userId(userId)
+                .instrumentId(instrumentId)
+                .eventType(PositionEventType.MARK_PRICE_UPDATED)
+                .deltaQuantity(BigDecimal.ZERO)
+                .deltaMargin(BigDecimal.ZERO)
+                .realizedPnl(BigDecimal.ZERO)
+                .tradeFee(BigDecimal.ZERO)
+                .fundingFee(BigDecimal.ZERO)
+                .newQuantity(newQuantity)
+                .newReservedQuantity(newReservedQuantity)
+                .newEntryPrice(newEntryPrice)
+                .newLeverage(newLeverage)
+                .newMargin(newMargin)
+                .newUnrealizedPnl(newUnrealizedPnl)
+                .newLiquidationPrice(newLiquidationPrice)
+                .referenceId(tradeId)
+                .referenceType(PositionReferenceType.MARK_PRICE_UPDATE)
+                .metadata("{\"marginRatio\": " + marginRatio + "}")
+                .occurredAt(occurredAt)
+                .build();
+    }
 }
diff --git a/...src/main/java/open/vincentf13/exchange/position/domain/service/PositionDomainService.java b/...src/main/java/open/vincentf13/exchange/position/domain/service/PositionDomainService.java
@@ -16,12 +16,14 @@
 import open.vincentf13.exchange.position.infra.cache.RiskLimitCache;
 import open.vincentf13.exchange.position.infra.persistence.po.PositionPO;
 import open.vincentf13.exchange.position.infra.persistence.repository.PositionEventRepository;
+import open.vincentf13.exchange.market.mq.event.MarkPriceUpdatedEvent;
 import open.vincentf13.exchange.position.infra.persistence.repository.PositionRepository;
 import open.vincentf13.exchange.position.sdk.rest.api.enums.PositionEventType;
 import open.vincentf13.exchange.position.sdk.rest.api.enums.PositionReferenceType;
 import open.vincentf13.sdk.core.exception.OpenException;
 import open.vincentf13.sdk.core.object.mapper.OpenObjectMapper;
 import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
 
 import java.math.BigDecimal;
 import java.math.RoundingMode;
@@ -45,6 +47,110 @@ public class PositionDomainService {
     private static final BigDecimal MAINTENANCE_MARGIN_RATE_DEFAULT = BigDecimal.valueOf(0.005);
     private static final BigDecimal CONTRACT_MULTIPLIER = BigDecimal.ONE;
 
+    @Transactional
+    public void handleMarkPriceUpdate(MarkPriceUpdatedEvent event) {
+        Long instrumentId = event.instrumentId();
+        BigDecimal markPrice = event.markPrice();
+        Instant eventTime = event.tradeExecutedAt();
+
+        markPriceCache.update(instrumentId, markPrice, eventTime);
+
+        List<Position> activePositions = positionRepository.findBy(
+                Wrappers.lambdaQuery(PositionPO.class)
+                        .eq(PositionPO::getInstrumentId, instrumentId)
+                        .eq(PositionPO::getStatus, PositionStatus.ACTIVE));
+
+        BigDecimal contractMultiplier = instrumentCache.get(instrumentId)
+                .map(instrument -> instrument.contractSize() != null ? instrument.contractSize() : CONTRACT_MULTIPLIER)
+                .orElse(CONTRACT_MULTIPLIER);
+
+        BigDecimal maintenanceMarginRate = riskLimitCache.get(instrumentId)
+                .map(riskLimit -> riskLimit.maintenanceMarginRate() != null ? riskLimit.maintenanceMarginRate() : MAINTENANCE_MARGIN_RATE_DEFAULT)
+                .orElse(MAINTENANCE_MARGIN_RATE_DEFAULT);
+
+        for (Position position : activePositions) {
+            updatePositionWithMarkPrice(position, markPrice, contractMultiplier, maintenanceMarginRate, event);
+        }
+    }
+
+    private void updatePositionWithMarkPrice(Position position, BigDecimal markPrice, BigDecimal contractMultiplier, BigDecimal maintenanceMarginRate, MarkPriceUpdatedEvent event) {
+        Position updatedPosition = OpenObjectMapper.convert(position, Position.class);
+        updatedPosition.setMarkPrice(markPrice);
+
+        BigDecimal quantity = safe(position.getQuantity());
+
+        // Skip if quantity is zero (should not happen for active positions but safe guard)
+        if (quantity.compareTo(BigDecimal.ZERO) == 0) {
+            return;
+        }
+
+        if (updatedPosition.getSide() == PositionSide.LONG) {
+            updatedPosition.setUnrealizedPnl(markPrice.subtract(updatedPosition.getEntryPrice())
+                    .multiply(quantity)
+                    .multiply(contractMultiplier));
+        } else {
+            updatedPosition.setUnrealizedPnl(updatedPosition.getEntryPrice().subtract(markPrice)
+                    .multiply(quantity)
+                    .multiply(contractMultiplier));
+        }
+
+        BigDecimal notional = markPrice.multiply(quantity).abs();
+        if (notional.compareTo(BigDecimal.ZERO) == 0) {
+            updatedPosition.setMarginRatio(BigDecimal.ZERO);
+        } else {
+            updatedPosition.setMarginRatio(updatedPosition.getMargin().add(updatedPosition.getUnrealizedPnl())
+                    .divide(notional, ValidationConstant.Names.MARGIN_RATIO_SCALE, RoundingMode.HALF_UP));
+        }
+
+        if (updatedPosition.getSide() == PositionSide.LONG) {
+            updatedPosition.setLiquidationPrice(
+                    updatedPosition.getEntryPrice()
+                            .subtract(updatedPosition.getMargin().divide(quantity, ValidationConstant.Names.COMMON_SCALE, RoundingMode.HALF_UP))
+                            .divide(BigDecimal.ONE.subtract(maintenanceMarginRate), ValidationConstant.Names.COMMON_SCALE, RoundingMode.HALF_UP)
+            );
+        } else {
+            updatedPosition.setLiquidationPrice(
+                    updatedPosition.getEntryPrice()
+                            .add(updatedPosition.getMargin().divide(quantity, ValidationConstant.Names.COMMON_SCALE, RoundingMode.HALF_UP))
+                            .divide(BigDecimal.ONE.add(maintenanceMarginRate), ValidationConstant.Names.COMMON_SCALE, RoundingMode.HALF_UP)
+            );
+        }
+
+        // Optimistic Locking Update
+        int expectedVersion = position.safeVersion();
+        updatedPosition.setVersion(expectedVersion + 1);
+        boolean updated = positionRepository.updateSelectiveBy(
+                updatedPosition,
+                Wrappers.<PositionPO>lambdaUpdate()
+                        .eq(PositionPO::getPositionId, updatedPosition.getPositionId())
+                        .eq(PositionPO::getVersion, expectedVersion));
+
+        if (!updated) {
+           // If concurrent update happens (e.g. user trades at the same time), we skip this mark price update
+           // as the trade event will update the position with latest data anyway.
+           // Or we could throw exception to retry, but for high freq mark price, skipping is acceptable.
+           // However, to be safe and consistent with other methods, we can log it.
+           return;
+        }
+
+        PositionEvent positionEvent = PositionEvent.createMarkPriceEvent(
+                updatedPosition.getPositionId(),
+                position.getUserId(),
+                position.getInstrumentId(),
+                updatedPosition.getQuantity(),
+                updatedPosition.getClosingReservedQuantity(),
+                updatedPosition.getEntryPrice(),
+                updatedPosition.getLeverage(),
+                updatedPosition.getMargin(),
+                updatedPosition.getUnrealizedPnl(),
+                updatedPosition.getMarginRatio(),
+                updatedPosition.getLiquidationPrice(),
+                event.tradeId(),
+                event.calculatedAt()
+        );
+        positionEventRepository.insert(positionEvent);
+    }
+
     public PositionSide toPositionSide(OrderSide orderSide) {
         if (orderSide == null) {
             return null;

diff --git a/...xchange-position/src/main/java/open/vincentf13/exchange/position/infra/PositionEvent.java b/...xchange-position/src/main/java/open/vincentf13/exchange/position/infra/PositionEvent.java
@@ -16,7 +16,8 @@ public enum PositionEvent implements OpenEvent {
     STARTUP_LOADING_RISK_LIMITS("StartupLoadingRiskLimits", "Loading risk limits from Risk service"),
     STARTUP_RISK_LIMITS_LOADED("StartupRiskLimitsLoaded", "Risk limits loaded successfully"),
     STARTUP_RISK_LIMIT_FETCH_FAILED("StartupRiskLimitFetchFailed", "Failed to fetch risk limit for instrument"),
-    STARTUP_RISK_LIMIT_LOAD_PARTIAL("StartupRiskLimitLoadPartial", "Partial risk limit loading");
+    STARTUP_RISK_LIMIT_LOAD_PARTIAL("StartupRiskLimitLoadPartial", "Partial risk limit loading"),
+    POSITION_MARK_PRICE_PAYLOAD_INVALID("PositionMarkPricePayloadInvalid", "Invalid MarkPriceUpdated payload");
 
     private final String event;
     private final String message;

diff --git a/.../vincentf13/exchange/position/infra/messaging/consumer/MarkPriceUpdatedEventListener.java b/.../vincentf13/exchange/position/infra/messaging/consumer/MarkPriceUpdatedEventListener.java
@@ -0,0 +1,34 @@
+package open.vincentf13.exchange.position.infra.messaging.consumer;
+
+import lombok.RequiredArgsConstructor;
+import open.vincentf13.exchange.market.mq.event.MarkPriceUpdatedEvent;
+import open.vincentf13.sdk.core.OpenValidator;
+import open.vincentf13.exchange.market.mq.topic.MarketTopics;
+import open.vincentf13.exchange.position.domain.service.PositionDomainService;
+import open.vincentf13.exchange.position.infra.PositionEvent;
+import open.vincentf13.sdk.core.log.OpenLog;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.support.Acknowledgment;
+import org.springframework.messaging.handler.annotation.Payload;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class MarkPriceUpdatedEventListener {
+
+    private final PositionDomainService positionDomainService;
+
+    @KafkaListener(topics = MarketTopics.Names.MARK_PRICE_UPDATED,
+            groupId = "${exchange.position.mark-price-updated.consumer-group:exchange-position-mark-price-updated}")
+    public void onMarkPriceUpdated(@Payload MarkPriceUpdatedEvent event,
+                                   Acknowledgment acknowledgment) {
+        try {
+            OpenValidator.validateOrThrow(event);
+            positionDomainService.handleMarkPriceUpdate(event);
+            acknowledgment.acknowledge();
+        } catch (Exception e) {
+            OpenLog.error(PositionEvent.POSITION_MARK_PRICE_PAYLOAD_INVALID, e, "event", event);
+            throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);
+        }
+    }
+}