feat: AMMs can specify a spread around their fair-price

commands/amend_amm.go

@@ -70,9 +70,17 @@ func checkAmendAMM(cmd *commandspb.AmendAMM) Errors {
 
 	if cmd.MinimumPriceChangeTrigger != nil {
 		if minPriceChange, err := num.DecimalFromString(*cmd.MinimumPriceChangeTrigger); err != nil {
-			errs.AddForProperty("submit_amm.mimimum_price_change_trigger", ErrIsNotValid)
+			errs.AddForProperty("amend_amm.mimimum_price_change_trigger", ErrIsNotValid)
 		} else if minPriceChange.LessThan(num.DecimalZero()) {
-			errs.AddForProperty("submit_amm.proposed_fee", ErrMustBePositiveOrZero)
+			errs.AddForProperty("amend_amm.mimimum_price_change_trigger", ErrMustBePositiveOrZero)
+		}
+	}
+
+	if cmd.Spread != nil {
+		if spread, err := num.DecimalFromString(*cmd.Spread); err != nil {
+			errs.AddForProperty("amend_amm.spread", ErrIsNotValid)
+		} else if spread.LessThan(num.DecimalZero()) {
+			errs.AddForProperty("amend_amm.spread", ErrMustBePositiveOrZero)
 		}
 	}
 

commands/submit_amm.go

@@ -72,6 +72,14 @@ func checkSubmitAMM(cmd *commandspb.SubmitAMM) Errors {
 		}
 	}
 
+	if cmd.Spread != nil {
+		if spread, err := num.DecimalFromString(*cmd.Spread); err != nil {
+			errs.AddForProperty("submit_amm.spread", ErrIsNotValid)
+		} else if spread.LessThan(num.DecimalZero()) {
+			errs.AddForProperty("submit_amm.spread", ErrMustBePositiveOrZero)
+		}
+	}
+
 	if cmd.ConcentratedLiquidityParameters == nil {
 		errs.FinalAddForProperty("submit_amm.concentrated_liquidity_parameters", ErrIsRequired)
 	} else {

core/events/amm_pool.go

@@ -55,6 +55,7 @@ func NewAMMPoolEvent(
 	lowerCurve *AMMCurve,
 	upperCurve *AMMCurve,
 	minimumPriceChangeTrigger num.Decimal,
+	spread num.Decimal,
 ) *AMMPool {
 	return &AMMPool{
 		Base: newBase(ctx, AMMPoolEvent),
@@ -71,6 +72,7 @@ func NewAMMPoolEvent(
 			LowerCurve:                lowerCurve.ToProtoEvent(),
 			UpperCurve:                upperCurve.ToProtoEvent(),
 			MinimumPriceChangeTrigger: minimumPriceChangeTrigger.String(),
+			Spread:                    spread.String(),
 		},
 	}
 }

core/execution/amm/engine.go

@@ -146,6 +146,8 @@ type Engine struct {
 	minCommitmentQuantum  *num.Uint
 	maxCalculationLevels  *num.Uint
 	allowedEmptyAMMLevels uint64
+
+	inAuction bool
 }
 
 func New(
@@ -211,13 +213,16 @@ func NewFromProto(
 		e.add(p)
 	}
 
+	e.inAuction = state.Auction
+
 	return e, nil
 }
 
 func (e *Engine) IntoProto() *v1.AmmState {
 	state := &v1.AmmState{
 		AmmPartyIds: make([]*v1.StringMapEntry, 0, len(e.ammParties)),
 		Pools:       make([]*v1.PoolMapEntry, 0, len(e.pools)),
+		Auction:     e.inAuction,
 	}
 
 	for k, v := range e.ammParties {
@@ -237,6 +242,20 @@ func (e *Engine) IntoProto() *v1.AmmState {
 	return state
 }
 
+func (e *Engine) EnterAuction() {
+	e.inAuction = true
+	for _, p := range e.poolsCpy {
+		p.inAuction = true
+	}
+}
+
+func (e *Engine) LeaveAuction() {
+	e.inAuction = false
+	for _, p := range e.poolsCpy {
+		p.inAuction = false
+	}
+}
+
 func (e *Engine) OnMinCommitmentQuantumUpdate(ctx context.Context, c *num.Uint) {
 	e.minCommitmentQuantum = c.Clone()
 }
@@ -349,7 +368,7 @@ func (e *Engine) GetVolumeAtPrice(price *num.Uint, side types.Side) uint64 {
 	vol := uint64(0)
 	for _, pool := range e.poolsCpy {
 		// get the pool's current price
-		best, ok := pool.BestPrice(types.OtherSide(side))
+		best, ok, _ := pool.BestPrice(types.OtherSide(side))
 		if !ok {
 			continue
 		}
@@ -382,8 +401,8 @@ func (e *Engine) submit(active []*Pool, agg *types.Order, inner, outer *num.Uint
 	for _, p := range active {
 		p.setEphemeralPosition()
 
-		price, ok := p.BestPrice(types.OtherSide(agg.Side))
-		if !ok {
+		price, volume := p.BestPriceAndVolume(types.OtherSide(agg.Side))
+		if volume == 0 {
 			continue
 		}
 
@@ -572,14 +591,20 @@ func (e *Engine) partition(agg *types.Order, inner, outer *num.Uint) ([]*Pool, [
 		// we hit a discontinuity where an AMM's two curves meet if we try to trade over its base-price
 		// so we partition the inner/outer price range at the base price so that we instead trade across it
 		// in two steps.
+		var addBase bool
 		boundary := p.upper.low
-		if inner != nil && outer != nil {
-			if boundary.LT(outer) && boundary.GT(inner) {
-				bounds[boundary.String()] = boundary.Clone()
-			}
-		} else if outer == nil && boundary.GT(inner) {
-			bounds[boundary.String()] = boundary.Clone()
-		} else if inner == nil && boundary.LT(outer) {
+		switch {
+		case inner != nil && outer != nil:
+			addBase = boundary.LT(outer) && boundary.GT(inner)
+		case inner == nil && outer == nil:
+			addBase = true
+		case outer == nil && boundary.GT(inner):
+			addBase = true
+		case inner == nil && boundary.LT(outer):
+			addBase = true
+		}
+
+		if addBase {
 			bounds[boundary.String()] = boundary.Clone()
 		}
 
@@ -696,13 +721,13 @@ func (e *Engine) Create(
 		e.positionFactor,
 		e.maxCalculationLevels,
 		e.allowedEmptyAMMLevels,
-		submit.SlippageTolerance,
-		submit.MinimumPriceChangeTrigger,
 	)
 	if err != nil {
 		return nil, err
 	}
 
+	pool.inAuction = e.inAuction
+
 	// sanity check, a *new* AMM should not already have a position. If it does it means that the party
 	// previously had an AMM but it was stopped/cancelled while still holding a position which should not happen.
 	// It should have either handed its position over to the liquidation engine, or be in reduce-only mode
@@ -874,6 +899,7 @@ func (e *Engine) sendUpdate(ctx context.Context, pool *Pool) {
 				TheoreticalPosition: pool.upper.pv,
 			},
 			pool.MinimumPriceChangeTrigger,
+			pool.Spread,
 		),
 	)
 }

core/execution/amm/engine_test.go

@@ -265,7 +265,7 @@ func testSubmitOrderAtBestPrice(t *testing.T) {
 	ensurePosition(t, tst.pos, 0, num.NewUint(0))
 	orders := tst.engine.SubmitOrder(agg, num.NewUint(2000), num.NewUint(2001))
 	require.Len(t, orders, 1)
-	assert.Equal(t, "2000", orders[0].Price.String())
+	assert.Equal(t, "2001", orders[0].Price.String())
 	assert.Equal(t, 11927, int(orders[0].Size))
 
 	bb, _, ba, _ := tst.engine.BestPricesAndVolumes()
@@ -360,7 +360,7 @@ func testSubmitOrderProRata(t *testing.T) {
 	orders := tst.engine.SubmitOrder(agg, num.NewUint(2010), num.NewUint(2020))
 	require.Len(t, orders, 3)
 	for _, o := range orders {
-		assert.Equal(t, "2000", o.Price.String())
+		assert.Equal(t, "2001", o.Price.String())
 		assert.Equal(t, uint64(222), o.Size)
 	}
 }
@@ -402,9 +402,9 @@ func testSubmitOrderAcrossAMMBoundary(t *testing.T) {
 	require.Len(t, orders, 6)
 
 	// first round, three orders moving all pool's to the upper boundary of the shortest
-	assert.Equal(t, "2049", orders[0].Price.String())
-	assert.Equal(t, "2049", orders[1].Price.String())
-	assert.Equal(t, "2049", orders[2].Price.String())
+	assert.Equal(t, "2048", orders[0].Price.String())
+	assert.Equal(t, "2048", orders[1].Price.String())
+	assert.Equal(t, "2048", orders[2].Price.String())
 
 	// second round, 2 orders moving all pool's to the upper boundary of the second shortest
 	assert.Equal(t, "2124", orders[3].Price.String())
@@ -452,9 +452,9 @@ func testSubmitOrderAcrossAMMBoundarySell(t *testing.T) {
 	require.Len(t, orders, 6)
 
 	// first round, three orders moving all pool's to the upper boundary of the shortest
-	assert.Equal(t, "1949", orders[0].Price.String())
-	assert.Equal(t, "1949", orders[1].Price.String())
-	assert.Equal(t, "1949", orders[2].Price.String())
+	assert.Equal(t, "1948", orders[0].Price.String())
+	assert.Equal(t, "1948", orders[1].Price.String())
+	assert.Equal(t, "1948", orders[2].Price.String())
 
 	// second round, 2 orders moving all pool's to the upper boundary of the second shortest
 	assert.Equal(t, "1874", orders[3].Price.String())
@@ -503,7 +503,7 @@ func TestBestPricesAndVolumeNearBound(t *testing.T) {
 	expectSubaccountCreation(t, tst, party, subAccount)
 	whenAMMIsSubmitted(t, tst, submit)
 
-	tst.pos.EXPECT().GetPositionsByParty(gomock.Any()).Times(10).Return(
+	tst.pos.EXPECT().GetPositionsByParty(gomock.Any()).Times(8).Return(
 		[]events.MarketPosition{&marketPosition{size: 0, averageEntry: num.NewUint(0)}},
 	)
 
@@ -514,7 +514,7 @@ func TestBestPricesAndVolumeNearBound(t *testing.T) {
 	assert.Equal(t, 1192, int(avolume))
 
 	// lets move its position so that the fair price is within one tick of the AMMs upper boundary
-	tst.pos.EXPECT().GetPositionsByParty(gomock.Any()).Times(10).Return(
+	tst.pos.EXPECT().GetPositionsByParty(gomock.Any()).Times(8).Return(
 		[]events.MarketPosition{&marketPosition{size: -222000, averageEntry: num.NewUint(0)}},
 	)
 
@@ -525,7 +525,7 @@ func TestBestPricesAndVolumeNearBound(t *testing.T) {
 	assert.Equal(t, 104, int(avolume))
 
 	// lets move its position so that the fair price is within one tick of the AMMs upper boundary
-	tst.pos.EXPECT().GetPositionsByParty(gomock.Any()).Times(10).Return(
+	tst.pos.EXPECT().GetPositionsByParty(gomock.Any()).Times(8).Return(
 		[]events.MarketPosition{&marketPosition{size: 270400, averageEntry: num.NewUint(0)}},
 	)
 
@@ -746,7 +746,7 @@ func testAMMSnapshot(t *testing.T) {
 	orders := tst.engine.SubmitOrder(agg, num.NewUint(2010), num.NewUint(2020))
 	require.Len(t, orders, 3)
 	for _, o := range orders {
-		assert.Equal(t, "2000", o.Price.String())
+		assert.Equal(t, "2001", o.Price.String())
 		assert.Equal(t, uint64(222), o.Size)
 	}