diff --git a/x/market/keeper/keeper.go b/x/market/keeper/keeper.go
index 92748408..0fffcf98 100644
--- a/x/market/keeper/keeper.go
+++ b/x/market/keeper/keeper.go
@@ -282,7 +282,7 @@ func (k *Keeper) NewOrderSingle(ctx sdk.Context, aggressiveOrder types.Order) (*
 				panic(err)
 			}
 
-			types.EmitFillEvent(ctx, *passiveOrder, stepSourceFilled.RoundInt(), stepDestinationFilled.RoundInt())
+			types.EmitFillEvent(ctx, *passiveOrder, false, stepSourceFilled.RoundInt(), stepDestinationFilled.RoundInt())
 
 			if passiveOrder.IsFilled() {
 				k.deleteOrder(ctx, passiveOrder)
@@ -298,7 +298,7 @@ func (k *Keeper) NewOrderSingle(ctx sdk.Context, aggressiveOrder types.Order) (*
 			stepDestinationFilled = stepSourceFilled
 		}
 
-		types.EmitFillEvent(ctx, aggressiveOrder, aggressiveSourceFilled, aggressiveDestinationFilled)
+		types.EmitFillEvent(ctx, aggressiveOrder, true, aggressiveSourceFilled, aggressiveDestinationFilled)
 		if aggressiveOrder.IsFilled() {
 			break
 		}
diff --git a/x/market/spec/03_events.md b/x/market/spec/03_events.md
index 6d80a77f..44c8154a 100644
--- a/x/market/spec/03_events.md
+++ b/x/market/spec/03_events.md
@@ -54,10 +54,11 @@ average_fill_price = destination_filled / source_filled
 | market | order_id           | {uniqueOrderId}           |
 | market | owner              | {ownerAddress}            |
 | market | client_order_id    | {clientOrderId}           |
+| market | aggressive         | {aggressive}              |
 | market | source_filled      | {sourceFilledAmount}      |
 | market | destination_filled | {destinationFilledAmount} |
 
-When the market module executes a trade, the orders on each side of the trade receive a fill event.
+When the market module executes a trade, the orders on each side of the trade receive a fill event. The order that initiated the trade will have `aggressive` set to true.
 
 Both `source_filled` and `destination_filled` are specific to a single trade, i.e. in contrast to the [Order Expired](#order-expired) event they are non-cumulative.
 
diff --git a/x/market/types/events.go b/x/market/types/events.go
index 7a59b949..c5e9bd64 100644
--- a/x/market/types/events.go
+++ b/x/market/types/events.go
@@ -6,6 +6,7 @@ package types
 
 import (
 	"fmt"
+	"strconv"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
@@ -24,6 +25,7 @@ const (
 	AttributeKeySourceFilled      = "source_filled"
 	AttributeKeyDestination       = "destination"
 	AttributeKeyDestinationFilled = "destination_filled"
+	AttributeKeyAggressive        = "aggressive"
 )
 
 func EmitAcceptEvent(ctx sdk.Context, order Order) {
@@ -55,13 +57,14 @@ func EmitExpireEvent(ctx sdk.Context, order Order) {
 	)
 }
 
-func EmitFillEvent(ctx sdk.Context, order Order, sourceFilled sdk.Int, destinationFilled sdk.Int) {
+func EmitFillEvent(ctx sdk.Context, order Order, aggressive bool, sourceFilled sdk.Int, destinationFilled sdk.Int) {
 	ctx.EventManager().EmitEvent(
 		sdk.NewEvent(EventTypeMarket,
 			sdk.NewAttribute(AttributeKeyAction, "fill"),
 			sdk.NewAttribute(AttributeKeyOrderID, fmt.Sprintf("%d", order.ID)),
 			sdk.NewAttribute(AttributeKeyOwner, order.Owner.String()),
 			sdk.NewAttribute(AttributeKeyClientOrderID, order.ClientOrderID),
+			sdk.NewAttribute(AttributeKeyAggressive, strconv.FormatBool(aggressive)),
 			sdk.NewAttribute(AttributeKeySourceFilled, fmt.Sprintf("%v%v", sourceFilled.String(), order.Source.Denom)),
 			sdk.NewAttribute(AttributeKeyDestinationFilled, fmt.Sprintf("%v%v", destinationFilled.String(), order.Destination.Denom)),
 		),