diff --git a/src/data/shiller.zig b/src/data/shiller.zig
index 7c878a6..d35625c 100644
--- a/src/data/shiller.zig
+++ b/src/data/shiller.zig
@@ -61,58 +61,56 @@ pub fn maxCycles(horizon: u16) usize {
 const csv_data = @embedFile("ie_data.csv");
 
 fn parseShillerData() []const ShillerYear {
-    @setEvalBranchQuota(1_000_000);
+    @setEvalBranchQuota(120_000);
 
-    // First pass: collect January rows with their cumulative indices.
-    // We need January Total Return Price (col 9), Bond Returns (col 17), CPI (col 4).
-    const JanRow = struct {
-        year: u16,
-        tr_price: f64, // cumulative S&P 500 total return index (nominal)
-        gs10: f64, // 10-year Treasury yield (percentage points)
-        cpi: f64,
-    };
+    var results: [200]ShillerYear = undefined;
+    var result_count: usize = 0;
 
-    var jan_rows: [200]JanRow = undefined;
-    var jan_count: usize = 0;
+    var prev_year: u16 = 0;
+    var prev_tr_price: f64 = 0;
+    var prev_gs10: f64 = 0;
+    var prev_cpi: f64 = 0;
 
-    var line_iter = LineIterator{ .data = csv_data };
-
-    // Skip header lines (first 8 lines are headers)
-    for (0..8) |_| {
-        _ = line_iter.next();
+    // Skip header (8 lines)
+    var pos: usize = 0;
+    var newlines: usize = 0;
+    while (pos < csv_data.len and newlines < 8) : (pos += 1) {
+        if (csv_data[pos] == '\n') newlines += 1;
     }
 
-    while (line_iter.next()) |line| {
-        if (line.len == 0) continue;
+    // Lines are ~135 bytes. After each January row, the next January is
+    // ~12 lines away. Skip 11 × min_line_length (~96) = 1056 bytes,
+    // then scan forward to the next line boundary. This avoids scanning
+    // ~90% of the file byte-by-byte.
+    const skip_bytes = 11 * 96;
 
-        // Parse the date column to check if this is a January row
+    while (pos < csv_data.len) {
+        // Find current line
+        const line_start = pos;
+        while (pos < csv_data.len and csv_data[pos] != '\n') pos += 1;
+        const line_end = if (pos > line_start and csv_data[pos - 1] == '\r') pos - 1 else pos;
+        if (pos < csv_data.len) pos += 1;
+
+        const line = csv_data[line_start..line_end];
+        if (line.len < 7) continue;
+
+        // Fast reject: date is "YYYY.01,"
+        if (line[4] != '.' or line[5] != '0' or line[6] != '1') continue;
+
+        const year = parseU16(line[0..4]) orelse continue;
+
+        // Parse fields for this January row
         var col_iter = CsvFieldIterator{ .data = line };
-        const date_field = col_iter.next() orelse continue; // col 0: Date
-        if (date_field.len == 0) continue;
-
-        // Date format is "YYYY.MM" where January = ".01", October = ".1"
-        // (October drops the leading zero). Check for exactly ".01".
-        const dot_pos = indexOf(date_field, '.') orelse continue;
-        const year_str = date_field[0..dot_pos];
-        const month_str = date_field[dot_pos + 1 ..];
-
-        const year = parseU16(year_str) orelse continue;
-
-        // January is exactly "01" (2 chars). ".1" = October, ".11" = November.
-        if (month_str.len != 2) continue;
-        const month = parseU16(month_str) orelse continue;
-        if (month != 1) continue;
-
-        // Skip to the columns we need
+        _ = col_iter.next(); // col 0: Date
         _ = col_iter.next(); // col 1: P
         _ = col_iter.next(); // col 2: D
         _ = col_iter.next(); // col 3: E
-        const cpi_field = col_iter.next() orelse continue; // col 4: CPI
-        _ = col_iter.next(); // col 5: Date Fraction
-        const gs10_field = col_iter.next() orelse continue; // col 6: Rate GS10
-        _ = col_iter.next(); // col 7: Real Price
-        _ = col_iter.next(); // col 8: Real Dividend
-        const tr_price_field = col_iter.next() orelse continue; // col 9: Total Return Price (nominal)
+        const cpi_field = col_iter.next() orelse continue;
+        _ = col_iter.next(); // col 5
+        const gs10_field = col_iter.next() orelse continue;
+        _ = col_iter.next(); // col 7
+        _ = col_iter.next(); // col 8
+        const tr_price_field = col_iter.next() orelse continue;
 
         const cpi = parseF64(stripSpaces(cpi_field)) orelse continue;
         const gs10 = parseF64(stripSpaces(gs10_field)) orelse continue;
@@ -120,44 +118,88 @@ fn parseShillerData() []const ShillerYear {
 
         if (cpi == 0.0 or tr_price == 0.0 or gs10 == 0.0) continue;
 
-        jan_rows[jan_count] = .{
-            .year = year,
-            .tr_price = tr_price,
-            .gs10 = gs10,
-            .cpi = cpi,
-        };
-        jan_count += 1;
+        // Compute return from previous January
+        if (prev_year > 0 and year == prev_year + 1) {
+            const cpi_change = (cpi / prev_cpi) - 1.0;
+            const real_sp500 = (tr_price / prev_tr_price) - 1.0;
+
+            results[result_count] = .{
+                .year = prev_year,
+                .sp500_total_return = (1.0 + real_sp500) * (1.0 + cpi_change) - 1.0,
+                .bond_total_return = prev_gs10 / 100.0,
+                .cpi_inflation = cpi_change,
+            };
+            result_count += 1;
+        }
+
+        prev_year = year;
+        prev_tr_price = tr_price;
+        prev_gs10 = gs10;
+        prev_cpi = cpi;
+
+        // Skip ahead ~11 months of data
+        pos = @min(pos + skip_bytes, csv_data.len);
+        // Realign to next line boundary
+        while (pos < csv_data.len and csv_data[pos] != '\n') pos += 1;
+        if (pos < csv_data.len) pos += 1;
     }
 
-    // Second pass: compute year-over-year returns from consecutive January values.
-    if (jan_count < 2) return &.{};
+    // Single pass: scan lines, parse January rows, compute returns on the fly.
+    while (pos < csv_data.len) {
+        const line_start = pos;
+        while (pos < csv_data.len and csv_data[pos] != '\n') pos += 1;
+        const line_end = if (pos > line_start and csv_data[pos - 1] == '\r') pos - 1 else pos;
+        if (pos < csv_data.len) pos += 1;
 
-    var results: [200]ShillerYear = undefined;
-    var result_count: usize = 0;
+        const line = csv_data[line_start..line_end];
+        if (line.len < 7) continue;
 
-    for (1..jan_count) |i| {
-        const prev = jan_rows[i - 1];
-        const curr = jan_rows[i];
+        // Fast reject: date is "YYYY.01," — check fixed offsets
+        if (line[4] != '.' or line[5] != '0' or line[6] != '1') continue;
 
-        // Ensure consecutive years
-        if (curr.year != prev.year + 1) continue;
+        const year = parseU16(line[0..4]) orelse continue;
 
-        const cpi_change = (curr.cpi / prev.cpi) - 1.0;
-        // TR Price is a real (inflation-adjusted) total return index.
-        // Convert to nominal: (1 + real) * (1 + inflation) - 1
-        const real_sp500 = (curr.tr_price / prev.tr_price) - 1.0;
-        const nominal_sp500 = (1.0 + real_sp500) * (1.0 + cpi_change) - 1.0;
+        // Parse fields for this January row
+        var col_iter = CsvFieldIterator{ .data = line };
+        _ = col_iter.next(); // col 0: Date
+        _ = col_iter.next(); // col 1: P
+        _ = col_iter.next(); // col 2: D
+        _ = col_iter.next(); // col 3: E
+        const cpi_field = col_iter.next() orelse continue;
+        _ = col_iter.next(); // col 5
+        const gs10_field = col_iter.next() orelse continue;
+        _ = col_iter.next(); // col 7
+        _ = col_iter.next(); // col 8
+        const tr_price_field = col_iter.next() orelse continue;
 
-        results[result_count] = .{
-            .year = prev.year,
-            .sp500_total_return = nominal_sp500,
-            .bond_total_return = prev.gs10 / 100.0, // GS10 yield as nominal bond return (FIRECalc convention)
-            .cpi_inflation = cpi_change,
-        };
-        result_count += 1;
+        const cpi = parseF64(stripSpaces(cpi_field)) orelse continue;
+        const gs10 = parseF64(stripSpaces(gs10_field)) orelse continue;
+        const tr_price = parseF64WithCommas(tr_price_field) orelse continue;
+
+        if (cpi == 0.0 or tr_price == 0.0 or gs10 == 0.0) continue;
+
+        // Compute return from previous January (if consecutive)
+        if (prev_year > 0 and year == prev_year + 1) {
+            const cpi_change = (cpi / prev_cpi) - 1.0;
+            const real_sp500 = (tr_price / prev_tr_price) - 1.0;
+
+            results[result_count] = .{
+                .year = prev_year,
+                .sp500_total_return = (1.0 + real_sp500) * (1.0 + cpi_change) - 1.0,
+                .bond_total_return = prev_gs10 / 100.0,
+                .cpi_inflation = cpi_change,
+            };
+            result_count += 1;
+        }
+
+        prev_year = year;
+        prev_tr_price = tr_price;
+        prev_gs10 = gs10;
+        prev_cpi = cpi;
     }
 
-    // Copy into a correctly-sized slice
+    if (result_count == 0) return &.{};
+
     const final = blk: {
         var arr: [result_count]ShillerYear = undefined;
         for (0..result_count) |i| {
@@ -170,22 +212,6 @@ fn parseShillerData() []const ShillerYear {
 
 // --- Comptime parsing helpers ---
 
-const LineIterator = struct {
-    data: []const u8,
-    pos: usize = 0,
-
-    fn next(self: *LineIterator) ?[]const u8 {
-        if (self.pos >= self.data.len) return null;
-        const start = self.pos;
-        while (self.pos < self.data.len and self.data[self.pos] != '\n') {
-            self.pos += 1;
-        }
-        const end = if (self.pos > start and self.data[self.pos - 1] == '\r') self.pos - 1 else self.pos;
-        if (self.pos < self.data.len) self.pos += 1; // skip \n
-        return self.data[start..end];
-    }
-};
-
 const CsvFieldIterator = struct {
     data: []const u8,
     pos: usize = 0,