diff --git a/README.md b/README.md
index bbe789f..6313542 100644
--- a/README.md
+++ b/README.md
@@ -122,8 +122,7 @@ the batch firm's list, at random but weighted:
   the type's max contracts); an instrument whose expected hold for the
   batch's leg is 12 h or more is out of the draw (e.g. 6E at a $1,000 leg,
   about a week).
-- Micros stay out of the draw; drain and extra-day legs trade the micro of a
-  listed product (MNQ when NQ is listed).
+- Micros stay out of the draw; drain and extra-day legs always trade MNQ.
 
 Every draw logs its odds. `GET /api/instruments` shows each firm's list with
 spread, daily move, hold and chance (`?simulate=10000` runs the real draw
diff --git a/lib/auto-trade.ts b/lib/auto-trade.ts
index 52d11db..6c90d99 100644
--- a/lib/auto-trade.ts
+++ b/lib/auto-trade.ts
@@ -23,7 +23,7 @@ import {
 } from './trading-logic';
 import { getSetting, setSetting } from './db';
 import type { LaneTick, TickReason } from './master-protocol';
-import { POINT_VALUES, housekeepingRoot, MAX_HOLD_HOURS } from './instrument-specs';
+import { POINT_VALUES, housekeepingRoot, HOUSEKEEPING_ROOT, MAX_HOLD_HOURS } from './instrument-specs';
 import { firmInstruments, drawFuturesInstrument, spreadBlock, type LegShape } from './instruments';
 import { recordEntry } from './trade-mix';
 import { errorMessage, isClientReady, isOrderNotPlaced, type PlatformClient, type PlatformContract, type PickContext } from './platform-client';
@@ -434,7 +434,7 @@ function releaseTradeMutex(lease: number, lane: string): void {
  *  housekeepingRoot); a DXtrade firm its current pick. */
 function housekeepingFor(firm: { platform: string; instruments?: string[]; bannedSymbols?: string[]; symbolMap?: Record<string, { symbol: string }[]> }): string {
     if (firm.platform === 'dxtrade') return '*';
-    return housekeepingRoot(firmInstruments(firm)) ?? 'MNQ';
+    return housekeepingRoot(firmInstruments(firm)) ?? HOUSEKEEPING_ROOT;
 }
 
 /** The instrument a leg actually trades: drain legs go on the firm's
diff --git a/lib/instrument-specs.ts b/lib/instrument-specs.ts
index 03c6d90..73b963e 100644
--- a/lib/instrument-specs.ts
+++ b/lib/instrument-specs.ts
@@ -227,21 +227,16 @@ export function pickByChance(chances: { symbol: string; chance: number }[], rand
     return chances.length > 0 ? chances[chances.length - 1].symbol : null;
 }
 
+/** What every futures firm's drain and extra-day legs trade. */
+export const HOUSEKEEPING_ROOT = 'MNQ';
+
 /**
- * What a firm's drain and extra-day legs trade — tiny, so a micro: MNQ when
- * NQ or MNQ is listed (as always), else the micro of a listed full-size
- * contract, else a listed micro, else the listed root with the smallest tick
- * value. null for an empty list.
+ * What a firm's drain and extra-day legs trade: always MNQ — tiny targets
+ * belong on a micro, whatever the firm lists for its full-size legs. null
+ * for an empty list: that firm trades nothing.
  */
 export function housekeepingRoot(listed: readonly string[]): string | null {
-    const roots = listed.filter((r) => CME_SPECS[r]);
-    if (roots.length === 0) return null;
-    if (roots.includes('NQ') || roots.includes('MNQ')) return 'MNQ';
-    const twin = roots.find((r) => MICRO_OF[r]);
-    if (twin) return MICRO_OF[twin];
-    const micro = roots.find((r) => CME_SPECS[r].micro);
-    if (micro) return micro;
-    return [...roots].sort((a, b) => tickValue(a) - tickValue(b))[0];
+    return listed.some((r) => CME_SPECS[r]) ? HOUSEKEEPING_ROOT : null;
 }
 
 const DXTRADE_SYMBOL = /^[A-Za-z0-9./_:-]{1,32}$/;
diff --git a/scripts/check-instruments.mjs b/scripts/check-instruments.mjs
index d23c390..26e2a76 100644
--- a/scripts/check-instruments.mjs
+++ b/scripts/check-instruments.mjs
@@ -140,12 +140,13 @@ test('10k seeded draws land on the chances', () => {
     assert.equal(pickByChance([], 0.5), null);
 });
 
-test('drain and extra-day legs: a micro of what is listed', () => {
+test('drain and extra-day legs: always MNQ', () => {
+    // Always MNQ, whatever the firm lists; nothing for a firm that lists nothing.
     assert.equal(housekeepingRoot(['NQ', 'GC', 'CL', '6E']), 'MNQ');
     assert.equal(housekeepingRoot(['MNQ']), 'MNQ');
-    assert.equal(housekeepingRoot(['GC', 'CL']), 'MGC');
-    assert.equal(housekeepingRoot(['6E', 'ZN']), '6E');   // no micro: the smallest tick value
-    assert.equal(housekeepingRoot(['MCL', 'ZB']), 'MCL');
+    assert.equal(housekeepingRoot(['GC', 'CL']), 'MNQ');
+    assert.equal(housekeepingRoot(['6E', 'ZN']), 'MNQ');
+    assert.equal(housekeepingRoot(['MCL', 'ZB']), 'MNQ');
     assert.equal(housekeepingRoot([]), null);
 });