diff --git a/backend/src/index.ts b/backend/src/index.ts
index 7abbdfa..dfabd52 100644
--- a/backend/src/index.ts
+++ b/backend/src/index.ts
@@ -31,6 +31,11 @@ const toPositiveNumber = (value: unknown): number | null => {
     return Number.isFinite(numeric) && numeric > 0 ? numeric : null;
 };
 
+const toNonNegativeNumber = (value: unknown): number | null => {
+    const numeric = Number(value);
+    return Number.isFinite(numeric) && numeric >= 0 ? numeric : null;
+};
+
 const normalizeTriggerMode = (value: unknown): 'dollar' | 'percent' | null => {
     const normalized = String(value || '').trim().toLowerCase();
     if (normalized === 'dollar' || normalized === 'percent') return normalized;
@@ -71,9 +76,9 @@ const shouldArmSimpleBuy = (entry: ManualEntryRecord): boolean => {
 
 const computeSimpleBuyTriggerPrice = (entry: ManualEntryRecord): number | null => {
     const referencePrice = toPositiveNumber(entry.reference_price);
-    const threshold = toPositiveNumber(entry.drop_threshold_for_buy);
+    const threshold = toNonNegativeNumber(entry.drop_threshold_for_buy);
     const mode = normalizeTriggerMode(entry.drop_trigger_mode);
-    if (!referencePrice || !threshold || !mode) return null;
+    if (!referencePrice || threshold === null || !mode) return null;
 
     if (mode === 'dollar') {
         const triggerPrice = referencePrice - threshold;
@@ -238,6 +243,7 @@ async function main() {
                 if (shouldArmSimpleBuy(entry)) {
                     const triggerPrice = computeSimpleBuyTriggerPrice(entry);
                     const desiredQty = toPositiveNumber(entry.quantity);
+                    const threshold = toNonNegativeNumber(entry.drop_threshold_for_buy);
                     if (!triggerPrice || !desiredQty) continue;
                     if (currentPrice > triggerPrice) continue;
 
@@ -245,8 +251,8 @@ async function main() {
                         symbol,
                         'buy',
                         desiredQty,
-                        'limit',
-                        triggerPrice,
+                        threshold === 0 ? 'market' : 'limit',
+                        threshold === 0 ? undefined : triggerPrice,
                         currentPrice,
                         entry.user_id
                     );
diff --git a/web/src/views/SimpleView.tsx b/web/src/views/SimpleView.tsx
index afa6b4d..736de20 100644
--- a/web/src/views/SimpleView.tsx
+++ b/web/src/views/SimpleView.tsx
@@ -62,6 +62,13 @@ function parsePositiveNumber(value: string): number | null {
   return Number.isFinite(parsed) && parsed > 0 ? parsed : null;
 }
 
+function parseNonNegativeNumber(value: string): number | null {
+  const trimmed = value.trim();
+  if (!trimmed) return null;
+  const parsed = Number(trimmed);
+  return Number.isFinite(parsed) && parsed >= 0 ? parsed : null;
+}
+
 function roundPrice(value: number): number {
   return Number(value.toFixed(4));
 }
@@ -80,8 +87,8 @@ function normalizeMode(value: unknown, fallback: TriggerMode = 'percent'): Trigg
 
 function computeBuyTriggerPrice(draft: SimpleSetupDraft): number | null {
   const currentMarketPrice = parsePositiveNumber(draft.currentMarketPrice);
-  const dropValue = parsePositiveNumber(draft.dropValue);
-  if (!currentMarketPrice || !dropValue) return null;
+  const dropValue = parseNonNegativeNumber(draft.dropValue);
+  if (!currentMarketPrice || dropValue === null) return null;
 
   if (draft.dropMode === 'dollar') {
     const trigger = currentMarketPrice - dropValue;
@@ -136,7 +143,7 @@ export function buildSimpleSetupPayload(input: {
     throw new Error('Sell setups require an existing Simple holding for this symbol.');
   }
 
-  if (side === 'buy' && !parsePositiveNumber(input.draft.dropValue)) {
+  if (side === 'buy' && parseNonNegativeNumber(input.draft.dropValue) === null) {
     throw new Error('Drop trigger is required for buy setups');
   }
 
@@ -154,7 +161,7 @@ export function buildSimpleSetupPayload(input: {
     entry_price: side === 'sell' ? holding!.entryPrice : null,
     reference_price: currentMarketPrice,
     gain_threshold_for_sell: profitValue,
-    drop_threshold_for_buy: side === 'buy' ? parsePositiveNumber(input.draft.dropValue) : null,
+    drop_threshold_for_buy: side === 'buy' ? parseNonNegativeNumber(input.draft.dropValue) : null,
     workflow_type: 'simple',
     simple_side: side,
     drop_trigger_mode: side === 'buy' ? input.draft.dropMode : null,
@@ -177,9 +184,13 @@ function buildPreviewText(draft: SimpleSetupDraft, holding: SimpleHolding | null
     const profitTargetPrice = computeProfitTargetPrice(triggerPrice, draft.profitMode, draft.profitValue);
     if (!triggerPrice) return `Buy ${symbol} after the configured drop trigger is hit.`;
 
-    const dropText = draft.dropMode === 'dollar'
-      ? `$${Number(draft.dropValue || 0).toFixed(2)} below current price`
-      : `${draft.dropValue || '0'}% below current price`;
+    const dropMagnitude = parseNonNegativeNumber(draft.dropValue);
+    const isImmediate = dropMagnitude === 0;
+    const dropText = isImmediate
+      ? 'at the current market reference'
+      : draft.dropMode === 'dollar'
+        ? `$${Number(draft.dropValue || 0).toFixed(2)} below current price`
+        : `${draft.dropValue || '0'}% below current price`;
     const profitText = draft.profitMode === 'dollar'
       ? `$${Number(draft.profitValue || 0).toFixed(2)} above purchase`
       : `${draft.profitValue || '0'}% above purchase`;
@@ -212,9 +223,9 @@ function buildDraftFromEntry(entry: ManualEntryPayload): SimpleSetupDraft {
     quantity: entry.quantity ? String(entry.quantity) : '',
     currentMarketPrice: entry.reference_price ? Number(entry.reference_price).toFixed(4) : '',
     dropMode: normalizeMode(entry.drop_trigger_mode, 'percent'),
-    dropValue: entry.drop_threshold_for_buy ? String(entry.drop_threshold_for_buy) : '',
+    dropValue: entry.drop_threshold_for_buy !== null && entry.drop_threshold_for_buy !== undefined ? String(entry.drop_threshold_for_buy) : '',
     profitMode: normalizeMode(entry.profit_target_mode, 'percent'),
-    profitValue: entry.gain_threshold_for_sell ? String(entry.gain_threshold_for_sell) : '',
+    profitValue: entry.gain_threshold_for_sell !== null && entry.gain_threshold_for_sell !== undefined ? String(entry.gain_threshold_for_sell) : '',
     notes: String(entry.notes || ''),
   };
 }
@@ -261,9 +272,11 @@ function describeSavedSetup(entry: ManualEntryPayload): string {
 
   if (side === 'buy') {
     const triggerPrice = computeBuyTriggerPrice(buildDraftFromEntry(entry));
-    const dropText = dropMode === 'dollar'
-      ? `$${dropValue.toFixed(2)} below`
-      : `${dropValue}% below`;
+    const dropText = dropValue === 0
+      ? 'at current reference'
+      : dropMode === 'dollar'
+        ? `$${dropValue.toFixed(2)} below`
+        : `${dropValue}% below`;
     const profitText = profitMode === 'dollar'
       ? `$${profitValue.toFixed(2)} above purchase`
       : `${profitValue}% above purchase`;
@@ -590,7 +603,7 @@ export function SimpleView() {
                   <Input
                     value={draft.dropValue}
                     onChange={(e) => updateDraft('dropValue', e.target.value)}
-                    placeholder={draft.dropMode === 'dollar' ? '5.00' : '8'}
+                    placeholder={draft.dropMode === 'dollar' ? '0.00' : '0'}
                   />
                 </label>
               </div>