diff --git a/src/analytics.ts b/src/analytics.ts
new file mode 100644
index 0000000..7433dc3
--- /dev/null
+++ b/src/analytics.ts
@@ -0,0 +1,120 @@
+import type { ProjectSummary, SessionSummary, TaskCategory } from './types.js'
+import { CATEGORY_LABELS } from './types.js'
+import { getShortModelName } from './models.js'
+
+export const TOP_OUTLIER_COUNT = 5
+export const OUTLIER_MULTIPLIER = 2
+
+export type OutlierSession = {
+  rank: number
+  project: string
+  sessionId: string
+  date: string
+  totalCostUSD: number
+  dominantActivity: string
+  isOutlier: boolean
+}
+
+export type ModelOneShotRow = {
+  model: string
+  sessions: number
+  oneShotTurns: number
+  editTurns: number
+  oneShotRate: number | null
+  costUSD: number
+}
+
+export function dominantActivity(session: SessionSummary): string {
+  let best: TaskCategory | null = null
+  let bestCost = 0
+  for (const [cat, data] of Object.entries(session.categoryBreakdown)) {
+    if (data.costUSD > bestCost) {
+      bestCost = data.costUSD
+      best = cat as TaskCategory
+    }
+  }
+  return best ? (CATEGORY_LABELS[best] ?? best) : 'General'
+}
+
+export function computeOutlierSessions(projects: ProjectSummary[]): OutlierSession[] {
+  const projectAvg = new Map<string, number>()
+  for (const p of projects) {
+    const avg = p.sessions.length > 0 ? p.totalCostUSD / p.sessions.length : 0
+    projectAvg.set(p.project, avg)
+  }
+
+  const all = projects.flatMap(p =>
+    p.sessions.map(s => ({ session: s, project: p.project }))
+  )
+  const sorted = [...all].sort((a, b) => b.session.totalCostUSD - a.session.totalCostUSD)
+  const top = sorted.slice(0, TOP_OUTLIER_COUNT)
+
+  return top.map(({ session, project }, i) => {
+    const avg = projectAvg.get(project) ?? 0
+    return {
+      rank: i + 1,
+      project,
+      sessionId: session.sessionId,
+      date: session.firstTimestamp ? session.firstTimestamp.slice(0, 10) : '----------',
+      totalCostUSD: session.totalCostUSD,
+      dominantActivity: dominantActivity(session),
+      isOutlier: avg > 0 && session.totalCostUSD > OUTLIER_MULTIPLIER * avg,
+    }
+  })
+}
+
+export function computeModelOneShotRates(projects: ProjectSummary[]): ModelOneShotRow[] {
+  const modelData = new Map<string, { oneShotTurns: number; editTurns: number; sessions: Set<string>; costUSD: number }>()
+
+  for (const project of projects) {
+    for (const session of project.sessions) {
+      for (const turn of session.turns) {
+        const primaryModel = turn.assistantCalls[0]
+          ? getShortModelName(turn.assistantCalls[0].model)
+          : null
+        if (!primaryModel) continue
+        const entry = modelData.get(primaryModel) ?? {
+          oneShotTurns: 0,
+          editTurns: 0,
+          sessions: new Set<string>(),
+          costUSD: 0,
+        }
+        if (turn.hasEdits) {
+          entry.editTurns++
+          if (turn.retries === 0) entry.oneShotTurns++
+        }
+        modelData.set(primaryModel, entry)
+      }
+      for (const [model, data] of Object.entries(session.modelBreakdown)) {
+        const entry = modelData.get(model) ?? {
+          oneShotTurns: 0,
+          editTurns: 0,
+          sessions: new Set<string>(),
+          costUSD: 0,
+        }
+        entry.costUSD += data.costUSD
+        entry.sessions.add(session.sessionId)
+        modelData.set(model, entry)
+      }
+    }
+  }
+
+  const rows: ModelOneShotRow[] = []
+  for (const [model, data] of modelData) {
+    rows.push({
+      model,
+      sessions: data.sessions.size,
+      oneShotTurns: data.oneShotTurns,
+      editTurns: data.editTurns,
+      oneShotRate: data.editTurns > 0 ? data.oneShotTurns / data.editTurns : null,
+      costUSD: data.costUSD,
+    })
+  }
+
+  return rows.sort((a, b) => {
+    if (a.oneShotRate === null && b.oneShotRate === null) return b.costUSD - a.costUSD
+    if (a.oneShotRate === null) return 1
+    if (b.oneShotRate === null) return -1
+    return b.oneShotRate - a.oneShotRate || b.costUSD - a.costUSD
+  })
+}
diff --git a/src/cli.ts b/src/cli.ts
index ac87127..d6766c6 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -10,6 +10,7 @@ import { buildMenubarPayload } from './menubar-json.js'
 import { addNewDays, getDaysInRange, loadDailyCache, saveDailyCache, withDailyCacheLock } from './daily-cache.js'
 import { aggregateProjectsIntoDays, buildPeriodDataFromDays } from './day-aggregator.js'
 import { CATEGORY_LABELS, type DateRange, type ProjectSummary, type TaskCategory } from './types.js'
+import { computeOutlierSessions, computeModelOneShotRates } from './analytics.js'
 import { renderDashboard } from './dashboard.js'
 import { runOptimize, scanAndDetect } from './optimize.js'
 import { getAllProviders } from './providers/index.js'
@@ -204,6 +205,25 @@ function buildJsonReport(projects: ProjectSummary[], period: string, periodKey:
     .sort((a, b) => b.cost - a.cost)
     .slice(0, 5)
 
+  const outlierSessions = computeOutlierSessions(projects).map(r => ({
+    rank: r.rank,
+    project: r.project,
+    sessionId: r.sessionId,
+    date: r.date,
+    cost: convertCost(r.totalCostUSD),
+    dominantActivity: r.dominantActivity,
+    isOutlier: r.isOutlier,
+  }))
+
+  const modelOneShotRates = computeModelOneShotRates(projects).map(r => ({
+    model: r.model,
+    sessions: r.sessions,
+    oneShotRate: r.oneShotRate !== null ? Math.round(r.oneShotRate * 1000) / 10 : null,
+    editTurns: r.editTurns,
+    oneShotTurns: r.oneShotTurns,
+    cost: convertCost(r.costUSD),
+  }))
+
   return {
     generated: new Date().toISOString(),
     currency: code,
@@ -229,6 +249,8 @@ function buildJsonReport(projects: ProjectSummary[], period: string, periodKey:
     mcpServers: sortedMap(mcpMap),
     shellCommands: sortedMap(bashMap),
     topSessions,
+    outlierSessions,
+    modelOneShotRates,
   }
 }
 
diff --git a/src/dashboard.tsx b/src/dashboard.tsx
index 21281f8..b66a488 100644
--- a/src/dashboard.tsx
+++ b/src/dashboard.tsx
@@ -3,6 +3,7 @@ import { homedir } from 'os'
 import React, { useState, useCallback, useEffect, useRef } from 'react'
 import { render, Box, Text, useInput, useApp, useWindowSize } from 'ink'
 import { CATEGORY_LABELS, type ProjectSummary, type TaskCategory } from './types.js'
+import { computeOutlierSessions, computeModelOneShotRates, TOP_OUTLIER_COUNT, OUTLIER_MULTIPLIER } from './analytics.js'
 import { formatCost, formatTokens } from './format.js'
 import { parseAllSessions, filterProjectsByName } from './parser.js'
 import { loadPricing } from './models.js'
@@ -374,37 +375,73 @@ function ToolBreakdown({ projects, pw, bw, title, filterPrefix }: { projects: Pr
   )
 }
 
-const TOP_SESSIONS_DATE_LEN = 10
 const TOP_SESSIONS_COST_COL = 8
-const TOP_SESSIONS_CALLS_COL = 6
+const TOP_SESSIONS_ACT_COL = 13
+
+const MODEL_ONESHOT_NAME_WIDTH = 14
+const MODEL_ONESHOT_RATE_COL = 7
+const MODEL_ONESHOT_SESS_COL = 6
+const MODEL_ONESHOT_COST_COL = 8
+const MODEL_ONESHOT_HIGH_THRESHOLD = 0.9
+const MODEL_ONESHOT_MID_THRESHOLD = 0.7
 
 function TopSessions({ projects, pw, bw }: { projects: ProjectSummary[]; pw: number; bw: number }) {
-  const allSessions = projects.flatMap(p =>
-    p.sessions.map(s => ({ ...s, projectName: p.project }))
-  )
-  const top = [...allSessions].sort((a, b) => b.totalCostUSD - a.totalCostUSD).slice(0, 5)
+  const rows = computeOutlierSessions(projects)
 
-  if (top.length === 0) {
-    return <Panel title="Top Sessions" color={PANEL_COLORS.sessions} width={pw}><Text dimColor>No sessions</Text></Panel>
+  if (rows.length === 0) {
+    return <Panel title={`Top ${TOP_OUTLIER_COUNT} Sessions by Cost`} color={PANEL_COLORS.sessions} width={pw}><Text dimColor>No sessions</Text></Panel>
   }
 
-  const maxCost = top[0].totalCostUSD
-  const nw = Math.max(8, pw - bw - TOP_SESSIONS_COST_COL - TOP_SESSIONS_CALLS_COL - 1 - PANEL_CHROME)
+  const maxCost = rows[0].totalCostUSD
+  const nw = Math.max(8, pw - bw - TOP_SESSIONS_COST_COL - TOP_SESSIONS_ACT_COL - 2 - PANEL_CHROME)
 
   return (
-    <Panel title="Top Sessions" color={PANEL_COLORS.sessions} width={pw}>
-      <Text dimColor wrap="truncate-end">{''.padEnd(bw + 1 + nw)}{'cost'.padStart(TOP_SESSIONS_COST_COL)}{'calls'.padStart(TOP_SESSIONS_CALLS_COL)}</Text>
-      {top.map((session, i) => {
-        const date = session.firstTimestamp
-          ? session.firstTimestamp.slice(0, TOP_SESSIONS_DATE_LEN)
-          : '----------'
-        const label = `${date} ${shortProject(session.projectName)}`
+    <Panel title={`Top ${TOP_OUTLIER_COUNT} Sessions by Cost`} color={PANEL_COLORS.sessions} width={pw}>
+      <Text dimColor wrap="truncate-end">{''.padEnd(bw + 1 + nw)}{'cost'.padStart(TOP_SESSIONS_COST_COL)}{' activity'.padEnd(TOP_SESSIONS_ACT_COL + 1)}</Text>
+      {rows.map((row, i) => {
+        const label = `${row.date} ${shortProject(row.project)}`
         return (
-          <Text key={`${session.sessionId}-${i}`} wrap="truncate-end">
-            <HBar value={session.totalCostUSD} max={maxCost} width={bw} />
+          <Text key={`${row.sessionId}-${i}`} wrap="truncate-end">
+            <HBar value={row.totalCostUSD} max={maxCost} width={bw} />
             <Text dimColor> {fit(label, nw - 1)}</Text>
-            <Text color={GOLD}>{formatCost(session.totalCostUSD).padStart(TOP_SESSIONS_COST_COL)}</Text>
-            <Text>{String(session.apiCalls).padStart(TOP_SESSIONS_CALLS_COL)}</Text>
+            <Text color={row.isOutlier ? '#F55B5B' : GOLD}>{formatCost(row.totalCostUSD).padStart(TOP_SESSIONS_COST_COL)}</Text>
+            <Text dimColor> {fit(row.dominantActivity, TOP_SESSIONS_ACT_COL)}</Text>
+          </Text>
+        )
+      })}
+      <Text dimColor wrap="truncate-end">red cost = outlier ({'>'}{OUTLIER_MULTIPLIER}x project avg)</Text>
+    </Panel>
+  )
+}
+
+function ModelOneShotBreakdown({ projects, pw, bw }: { projects: ProjectSummary[]; pw: number; bw: number }) {
+  const rows = computeModelOneShotRates(projects)
+
+  if (rows.length === 0) {
+    return <Panel title="One-Shot Rate by Model" color={PANEL_COLORS.model} width={pw}><Text dimColor>No model data</Text></Panel>
+  }
+
+  const maxCost = Math.max(...rows.map(r => r.costUSD))
+
+  return (
+    <Panel title="One-Shot Rate by Model" color={PANEL_COLORS.model} width={pw}>
+      <Text dimColor wrap="truncate-end">{''.padEnd(bw + 1 + MODEL_ONESHOT_NAME_WIDTH)}{'cost'.padStart(MODEL_ONESHOT_COST_COL)}{'sess'.padStart(MODEL_ONESHOT_SESS_COL)}{'1-shot'.padStart(MODEL_ONESHOT_RATE_COL)}</Text>
+      {rows.map((row, i) => {
+        const rateLabel = row.oneShotRate !== null ? `${Math.round(row.oneShotRate * 100)}%` : '-'
+        const rateColor = row.oneShotRate === null
+          ? DIM
+          : row.oneShotRate >= MODEL_ONESHOT_HIGH_THRESHOLD
+            ? '#5BF58C'
+            : row.oneShotRate >= MODEL_ONESHOT_MID_THRESHOLD
+              ? ORANGE
+              : '#F55B5B'
+        return (
+          <Text key={`${row.model}-${i}`} wrap="truncate-end">
+            <HBar value={row.costUSD} max={maxCost} width={bw} />
+            <Text> {fit(row.model, MODEL_ONESHOT_NAME_WIDTH)}</Text>
+            <Text color={GOLD}>{formatCost(row.costUSD).padStart(MODEL_ONESHOT_COST_COL)}</Text>
+            <Text>{String(row.sessions).padStart(MODEL_ONESHOT_SESS_COL)}</Text>
+            <Text color={rateColor}>{rateLabel.padStart(MODEL_ONESHOT_RATE_COL)}</Text>
           </Text>
         )
       })}
@@ -565,6 +602,7 @@ function DashboardContent({ projects, period, columns, activeProvider, budgets }
       <Row wide={wide} width={dashWidth}><DailyActivity projects={projects} days={days} pw={pw} bw={barWidth} /><ProjectBreakdown projects={projects} pw={pw} bw={barWidth} budgets={budgets} /></Row>
       <TopSessions projects={projects} pw={dashWidth} bw={barWidth} />
       <Row wide={wide} width={dashWidth}><ActivityBreakdown projects={projects} pw={pw} bw={barWidth} /><ModelBreakdown projects={projects} pw={pw} bw={barWidth} /></Row>
+      <ModelOneShotBreakdown projects={projects} pw={dashWidth} bw={barWidth} />
       {isCursor ? (
         <ToolBreakdown projects={projects} pw={dashWidth} bw={barWidth} title="Languages" filterPrefix="lang:" />
       ) : (
diff --git a/tests/analytics.test.ts b/tests/analytics.test.ts
new file mode 100644
index 0000000..4893b7c
--- /dev/null
+++ b/tests/analytics.test.ts
@@ -0,0 +1,169 @@
+import { describe, it, expect } from 'vitest'
+import {
+  computeOutlierSessions,
+  computeModelOneShotRates,
+  dominantActivity,
+  TOP_OUTLIER_COUNT,
+  OUTLIER_MULTIPLIER,
+} from '../src/analytics.js'
+import type { ClassifiedTurn, ParsedApiCall, ProjectSummary, SessionSummary, TokenUsage } from '../src/types.js'
+
+const EMPTY_CATS: SessionSummary['categoryBreakdown'] = {
+  coding: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  debugging: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  feature: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  refactoring: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  testing: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  exploration: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  planning: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  delegation: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  git: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  'build/deploy': { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  conversation: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  brainstorming: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+  general: { turns: 0, costUSD: 0, retries: 0, editTurns: 0, oneShotTurns: 0 },
+}
+
+function makeSession(id: string, cost: number, firstTs = '2026-04-10T10:00:00Z'): SessionSummary {
+  return {
+    sessionId: id, project: 'p', firstTimestamp: firstTs, lastTimestamp: firstTs,
+    totalCostUSD: cost, totalInputTokens: 0, totalOutputTokens: 0,
+    totalCacheReadTokens: 0, totalCacheWriteTokens: 0, apiCalls: 1,
+    turns: [], modelBreakdown: {}, toolBreakdown: {}, mcpBreakdown: {},
+    bashBreakdown: {}, categoryBreakdown: structuredClone(EMPTY_CATS),
+  }
+}
+
+function makeProject(name: string, sessions: SessionSummary[]): ProjectSummary {
+  const totalCostUSD = sessions.reduce((s, x) => s + x.totalCostUSD, 0)
+  return { project: name, projectPath: name, sessions, totalCostUSD, totalApiCalls: sessions.length }
+}
+
+describe('dominantActivity', () => {
+  it('returns label of highest-cost category', () => {
+    const s = makeSession('s1', 10)
+    s.categoryBreakdown.coding.costUSD = 5
+    s.categoryBreakdown.debugging.costUSD = 8
+    expect(dominantActivity(s)).toBe('Debugging')
+  })
+
+  it('returns General for empty categoryBreakdown costs', () => {
+    const s = makeSession('s1', 0)
+    expect(dominantActivity(s)).toBeTypeOf('string')
+  })
+})
+
+describe('computeOutlierSessions', () => {
+  it('returns at most TOP_OUTLIER_COUNT', () => {
+    const sessions = Array.from({ length: 8 }, (_, i) => makeSession(`s${i}`, i + 1))
+    const rows = computeOutlierSessions([makeProject('p', sessions)])
+    expect(rows.length).toBe(TOP_OUTLIER_COUNT)
+  })
+
+  it('sorts by cost descending', () => {
+    const sessions = [makeSession('a', 3), makeSession('b', 10), makeSession('c', 5)]
+    const rows = computeOutlierSessions([makeProject('p', sessions)])
+    expect(rows.map(r => r.sessionId)).toEqual(['b', 'c', 'a'])
+  })
+
+  it('flags isOutlier when cost > OUTLIER_MULTIPLIER x project avg', () => {
+    const sessions = [
+      makeSession('big', 100),
+      makeSession('s1', 10),
+      makeSession('s2', 10),
+      makeSession('s3', 10),
+    ]
+    const rows = computeOutlierSessions([makeProject('p', sessions)])
+    const big = rows.find(r => r.sessionId === 'big')!
+    expect(big.isOutlier).toBe(true)
+    const s1 = rows.find(r => r.sessionId === 's1')!
+    expect(s1.isOutlier).toBe(false)
+    expect(OUTLIER_MULTIPLIER).toBe(2)
+  })
+
+  it('isOutlier is false for a single-session project (no variance)', () => {
+    const rows = computeOutlierSessions([makeProject('p', [makeSession('only', 5)])])
+    expect(rows[0].isOutlier).toBe(false)
+  })
+
+  it('returns empty array for empty projects', () => {
+    expect(computeOutlierSessions([])).toEqual([])
+  })
+
+  it('includes YYYY-MM-DD date from firstTimestamp', () => {
+    const s = makeSession('s', 1, '2026-04-10T15:30:00Z')
+    const rows = computeOutlierSessions([makeProject('p', [s])])
+    expect(rows[0].date).toBe('2026-04-10')
+  })
+})
+
+function makeTokenUsage(): TokenUsage {
+  return {
+    inputTokens: 0,
+    outputTokens: 0,
+    cacheCreationInputTokens: 0,
+    cacheReadInputTokens: 0,
+    cachedInputTokens: 0,
+    reasoningTokens: 0,
+    webSearchRequests: 0,
+  }
+}
+
+function makeApiCall(model: string): ParsedApiCall {
+  return {
+    provider: 'claude',
+    model,
+    usage: makeTokenUsage(),
+    costUSD: 0,
+    tools: [],
+    mcpTools: [],
+    hasAgentSpawn: false,
+    hasPlanMode: false,
+    speed: 'standard',
+    timestamp: '2026-04-10T10:00:00Z',
+    bashCommands: [],
+    deduplicationKey: `${model}-0`,
+  }
+}
+
+function makeTurn(model: string, hasEdits: boolean, retries: number): ClassifiedTurn {
+  return {
+    userMessage: '',
+    assistantCalls: [makeApiCall(model)],
+    timestamp: '2026-04-10T10:00:00Z',
+    sessionId: 's1',
+    category: 'coding',
+    retries,
+    hasEdits,
+  }
+}
+
+describe('computeModelOneShotRates', () => {
+  it('returns one-shot rate per model', () => {
+    const s = makeSession('s1', 10)
+    s.modelBreakdown = { 'Sonnet 4.5': { calls: 3, costUSD: 10, tokens: makeTokenUsage() } }
+    s.turns = [
+      makeTurn('claude-sonnet-4-5', true, 0),
+      makeTurn('claude-sonnet-4-5', true, 1),
+      makeTurn('claude-sonnet-4-5', true, 0),
+    ]
+    const rows = computeModelOneShotRates([makeProject('p', [s])])
+    const sonnet = rows.find(r => r.model === 'Sonnet 4.5')
+    expect(sonnet).toBeDefined()
+    expect(sonnet!.oneShotTurns).toBe(2)
+    expect(sonnet!.editTurns).toBe(3)
+    expect(sonnet!.oneShotRate).toBeCloseTo(2 / 3)
+  })
+
+  it('null oneShotRate when no edit turns', () => {
+    const s = makeSession('s1', 5)
+    s.modelBreakdown = { 'Haiku': { calls: 1, costUSD: 5, tokens: makeTokenUsage() } }
+    s.turns = []
+    const rows = computeModelOneShotRates([makeProject('p', [s])])
+    expect(rows[0]?.oneShotRate).toBeNull()
+  })
+
+  it('returns empty for empty projects', () => {
+    expect(computeModelOneShotRates([])).toEqual([])
+  })
+})