phase-6: typescript introduction

server/market/MarketRegime.ts

@@ -0,0 +1,74 @@
+import { SECTOR, ASSET_TYPE, REGIME } from '../config/constants.js';
+import type { MarketContext, AssetType } from '../types.js';
+
+interface InflatedOverrides {
+  gates: Record<string, number>;
+  thresholds: Record<string, number>;
+}
+
+export class MarketRegime {
+  private marketPE: number;
+  private techPE: number;
+  private reitYield: number;
+  private igSpread: number;
+  private rateRegime: string;
+  private volatilityRegime: string;
+
+  constructor(marketContext: Partial<MarketContext>) {
+    const b = marketContext?.benchmarks ?? ({} as MarketContext['benchmarks']);
+    this.marketPE = b.marketPE ?? 22;
+    this.techPE = b.techPE ?? 30;
+    this.reitYield = b.reitYield ?? 3.5;
+    this.igSpread = b.igSpread ?? 1.0;
+    this.rateRegime = marketContext?.rateRegime ?? REGIME.NORMAL;
+    this.volatilityRegime = marketContext?.volatilityRegime ?? REGIME.NORMAL;
+  }
+
+  getInflatedOverrides(type: AssetType, sector?: string): InflatedOverrides {
+    if (type === ASSET_TYPE.STOCK) return this._stock(sector);
+    if (type === ASSET_TYPE.ETF) return this._etf();
+    if (type === ASSET_TYPE.BOND) return this._bond();
+    return { gates: {}, thresholds: {} };
+  }
+
+  private _stock(sector?: string): InflatedOverrides {
+    if (sector === SECTOR.REIT) {
+      return {
+        gates: {},
+        thresholds: {
+          minYield: +(this.reitYield * (this.rateRegime === REGIME.HIGH ? 0.95 : 0.85)).toFixed(2),
+          maxPFFO: 20,
+        },
+      };
+    }
+    if (sector === SECTOR.TECHNOLOGY) {
+      return {
+        gates: {
+          maxPERatio: Math.round(this.techPE * 1.3),
+          maxPegGate: +(this.techPE / 15).toFixed(1),
+        },
+        thresholds: {},
+      };
+    }
+    const peMultiplier = this.rateRegime === REGIME.HIGH ? 1.2 : 1.5;
+    return {
+      gates: {
+        maxPERatio: Math.round(this.marketPE * peMultiplier),
+        maxPegGate: +(this.marketPE / 12).toFixed(1),
+      },
+      thresholds: {},
+    };
+  }
+
+  private _etf(): InflatedOverrides {
+    return { gates: { maxExpenseRatio: 0.75 }, thresholds: { minYield: 0.5 } };
+  }
+
+  private _bond(): InflatedOverrides {
+    const spreadMultiplier = this.rateRegime === REGIME.HIGH ? 0.9 : 0.8;
+    return {
+      gates: {},
+      thresholds: { minSpread: +(this.igSpread * spreadMultiplier).toFixed(2) },
+    };
+  }
+}