Period 15 Review: Magic Formula's Mining Rebound Powers a Stunning Turnaround as Quality Growth Posts Its Worst Period Yet

Period 15 covers July 18 to July 25, 2026 — seven days that flipped Period 14's script almost stock for stock. Five screens were positive, two negative, and the spread between best and worst widened slightly to 7.63 percentage points — Magic Formula at +4.17% and Quality Growth at −3.46% — continuing the widening trend that began in Period 14 after three periods of narrowing (9.00 in Period 11, 6.06 in Period 12, 3.42 in Period 13, 6.81 in Period 14). Both benchmarks closed negative again, the S&P 500 at −0.61% and the NASDAQ at −2.13%, the second straight period both indices fell together.

The period's headline is Magic Formula's reversal: the same gold, silver, and shipping names that produced its worst-ever breadth in Period 14 — ORLA, OGC, IAG, CGAU — bounced back together, and this time HMY and INSW joined the rally rather than sitting it out. Eleven of its twelve positions closed positive, the screen's best breadth in the journal. Meanwhile Quality Growth, last period's winner, fell hardest: DAVE, the position that single-handedly carried its +1.57% win in Period 14, reversed to −8.54%, and SEZL's −11.90% was the worst single position result posted by any screen this period.

Period 15 Returns: Magic Formula Surges as Quality Growth Falls Hardest

Magic Formula topped the table at +4.17%, followed by CANSLIM Rocket at +2.26% and Schloss Dividend at +2.05%. Lunch added +1.51% and Burry Value squeaked out +0.10%, leaving five of seven screens positive. Only Piotroski F-Score (−1.24%) and Quality Growth (−3.46%) closed in the red, with Quality Growth posting by far the week's worst result — a sharp reversal from its +1.57% win last period.

Magic Formula's +4.17% was its best result in the journal, led by HMY (Gold Fields), which gained +8.33%, from $14.65 to $15.87, contributing approximately +0.64 percentage points at the screen's 7.69% equal weight. ORLA (Orla Mining) added +7.55% (+0.58 points), from $8.61 to $9.26 — a complete reversal from its −11.78% collapse in Period 13 — CGAU (Centerra Gold) rose +7.29% (+0.56 points), and INSW (International Seaways) gained +6.36% (+0.49 points). DHT (DHT Holdings) and OGC (OceanaGold) each added roughly +0.46 points. Against these, only FHI (Federated Hermes) fell, down −1.31% (−0.10 points). Eleven of twelve retained positions closed positive, the screen's best breadth in the journal. CALM (Cal-Maine Foods) exited at the sell fee — the same day it also exited Burry Value Screen, dissolving their shared overlap position; no new positions entered, shrinking the screen from thirteen to twelve.

CANSLIM's +2.26% mirrored Magic Formula's pattern almost exactly: the stocks that caused Period 14's collapse led the rebound. MU (Micron Technology) gained +8.48%, from $848.95 to $920.95, contributing approximately +0.42 percentage points at the 5% weight, reversing the −13.31% slide that anchored last period's selloff. ERO (Ero Copper) added +7.67% (+0.38 points), DY (Dycom Industries) rose +5.58% (+0.28 points), and PAAS (Pan American Silver) and HALO (Halozyme Therapeutics) each contributed roughly +0.27 points. Against these, GLW (Corning) fell −5.15% (−0.26 points) — its fourth straight negative period, though a fraction of Period 14's −19.01% drop — and LRCX (Lam Research) gave back −2.58% (−0.13 points). Fourteen of nineteen retained positions closed positive, a sharp improvement from four of nineteen last period. SMCI (Super Micro Computer) exited at the sell fee; CPAC (Cemex) enters the screen for Period 16, leaving CANSLIM at twenty names.

Schloss Dividend's +2.05% was its third positive result in four periods, led by DAC (Danaos), which surged +11.40%, from $125.87 to $140.22, contributing approximately +1.04 percentage points at the 9.09% weight. TX (Ternium) added +5.82% (+0.53 points) and JOYY (JOYY Inc.) gained +5.54% (+0.50 points). Against these, ATHM (Autohome) fell −1.95% (−0.18 points) and MTH (Meritage Homes) declined −1.64% (−0.15 points). Eight of eleven positions closed positive. All eleven positions were retained for the first time in the journal — the screen's first period of perfect retention.

Magic Formula's +4.17% is built from the same four stocks — HMY, ORLA, CGAU, and IAG — that combined for more than half of its worst breadth on record just one week earlier. What sank the screen in Period 14 lifted it clean off the bottom in Period 15.

Lunch's +1.51% reversed its two-period slide, led by AEM (Agnico Eagle), which gained +5.96%, from $136.97 to $145.13, contributing approximately +0.40 percentage points at the 6.67% weight — the same stock that had been one of the screen's worst positions in Period 14. PAAS (Pan American Silver) added +5.41% (+0.36 points), FSM (Fortuna Silver) gained +4.78% (+0.32 points), and CVE (Cenovus Energy) rose +4.76% (+0.32 points). Against these, ESTC (Elastic) fell −4.72% (−0.31 points) and KSPI (Kaspi.kz) declined −2.41% (−0.16 points). Nine of fourteen retained positions closed positive. TFPM (Triple Flag Precious Metals) exited at the sell fee; BVN (Compañía de Minas Buenaventura), HRMY (Harmony Biosciences), PATH (UiPath), and TTD (The Trade Desk) enter the screen for Period 16, growing Lunch from fifteen to eighteen names — its largest single-period expansion since Period 12.

Burry Value's +0.10% masked a wide spread across its thirty-seven positions. MLI (Mueller Industries) led with +8.08%, from $59.13 to $63.91, contributing approximately +0.22 percentage points at the 2.70% weight. B (Barnes Group) added +6.24% (+0.17 points) and AEM (Agnico Eagle) gained +5.96% (+0.16 points). Against these, NTES (NetEase) fell −8.94% (−0.24 points), the period's single worst position-level drag for the screen, and DOCS (Doximity) declined −5.11% (−0.14 points). Twelve of thirty-two retained positions closed positive. Five positions — AUPH (Aurinia Pharmaceuticals), CALM (Cal-Maine Foods), DECK (Deckers Brands), GGG (Graco), and PHM (PulteGroup) — exited at the sell fee, the screen's largest single-period contraction since Period 5; APPF (AppFolio) and HRMY (Harmony Biosciences) enter the screen for Period 16, leaving Burry at thirty-four names.

Piotroski's −1.24% reversed its best result in three periods, dragged down by WDH (Waterdrop), which fell −5.08%, from $1.18 to $1.12, subtracting approximately −0.36 percentage points at the 7.14% weight. YALA (Yalla Group) declined −3.72% (−0.27 points) and NOAH (Noah Holdings) gave back −3.60% (−0.26 points). Against these, GASS (StealthGas) gained +3.52% (+0.25 points) and SD (SandRidge Energy) added +1.39% (+0.10 points). Four of twelve retained positions closed positive, the screen's weakest breadth since Period 5. ASC (ArcelorMittal South Africa) and KE (KE Holdings) both exited at the sell fee — ASC's second exit from the screen in three periods — leaving Piotroski at twelve names heading into Period 16 with no new entrants.

Quality Growth's −3.46% was its worst period on record, dragged down by SEZL (Sezzle), which fell −11.90%, from $174.67 to $153.89, subtracting approximately −1.49 percentage points at the screen's 12.5% weight — the single largest position-level drag of any screen this period. DAVE (Dave Inc.) reversed hardest of all, falling −8.54% (−1.07 points) from $440.42 to $402.81, exactly one period after its +9.90% surge carried the entire screen to victory. APP (AppLovin), added to the screen for Period 15 only last week, fell −7.67% (−0.96 points) in its debut, from $424.54 to $391.98. AUPH (Aurinia Pharmaceuticals) added a further −3.82% (−0.48 points). Only CNX (CNX Resources, +3.03%) and NBIX (Neurocrine Biosciences, +2.86%) closed positive — two of seven retained positions, the screen's worst breadth since Period 8. AGI (Alamos Gold), which had joined the screen only one period earlier, exited at the sell fee; ELMD (Electromed) enters for Period 16.

Retention: Schloss Reaches Perfect Retention as Last Period's Leaders Turn Over

Period 15 handed perfect retention to a different screen than last time. Schloss Dividend held 100% of its starting positions for the first time in the journal, while Magic Formula and Quality Growth — both perfect in Period 14 — each turned over a position this period. Piotroski F-Score posted the field's lowest retention at 85.7%, narrowly behind Burry Value at 86.5%.

No screen repeated its Period 14 retention rank exactly. Schloss Dividend improved the most, from 91.7% to a clean 100%, while Magic Formula and Quality Growth both slipped from perfect scores after a single reshuffle apiece. The spread widened slightly too: Period 14's retention figures ranged from 88.2% to 100% (an 11.8-point spread), while Period 15 ranges from 85.7% to 100% (a 14.3-point spread), with every screen but Schloss turning over at least one name.

Cumulative Scoreboard: Quality Growth Still Leads, but Piotroski Falls to Last

Quality Growth's loss trimmed its cumulative return from +21.84% to +17.62%, its steepest single-period decline of the journal, though it remains the only screen ahead of both benchmarks by a wide margin. Magic Formula's +4.17% pushed its cumulative return from −12.19% to −8.52%, vaulting it past Piotroski F-Score (−13.00%, down from −11.91% after Period 15's −1.24%) and handing Piotroski last place among the seven screens for the first time in the journal.

CANSLIM's +2.26% lifted its cumulative return to +4.84% from +2.52%, staying in third place but narrowing the gap to Schloss Dividend (+7.70%, up from +5.54% after its own +2.05%). Burry Value's +0.10% nudged its cumulative return to +1.08% from +0.98%, holding fourth, while Lunch's +1.51% trimmed its cumulative loss to −1.79% from −3.25%, its best two-period stretch since Period 11-12. Piotroski's modest −1.24% was enough to drop it to last place only because Magic Formula's gain was so much larger — a near-exact repeat of the dynamic that separated these two screens in Period 14, with the roles reversed.

Against benchmarks, nearly every screen's alpha improved simply because both indices fell. Magic Formula's cumulative alpha widened positive by the most of any screen, from −22.16/−24.63 points to −17.82/−18.56 versus the S&P 500 and NASDAQ respectively — a swing of more than four points on the S&P side and six on the NASDAQ side. Schloss improved from −4.43/−6.90 to −1.60/−2.34, CANSLIM from −7.45/−9.92 to −4.46/−5.20, Burry from −8.99/−11.46 to −8.22/−8.96, and Lunch from −13.22/−15.69 to −11.09/−11.83. Only two screens moved the other way: Quality Growth's alpha narrowed from +11.87/+9.40 to +8.32/+7.58 as its own loss outpaced the benchmarks' declines, and Piotroski's alpha slipped slightly versus the S&P 500 (from −21.88 to −22.30) even as it improved versus the NASDAQ (from −24.35 to −23.04) — a reminder that a screen's alpha can move in opposite directions against the two benchmarks in the same period.

Overlap: Eight Stocks as Lunch Becomes the Journal's Hub

The July 25 snapshot shows eight stocks in two or more screens, down from nine on July 18. Three names dropped out together: AUPH exited Burry Value Screen (dissolving its pairing with Quality Growth), AGI exited Quality Growth (dissolving its pairing with CANSLIM Rocket), and CALM exited both Burry Value Screen and Magic Formula on the same day, erasing that overlap entirely rather than just shrinking it. Taking their place, HRMY re-entered both Burry Value Screen and Lunch, and BVN — already held in Magic Formula — was added to Lunch, creating a new pairing between the two.

Lunch now anchors seven of the eight overlap pairs — AEM, CPRX, FSM, and HRMY are all shared with Burry Value alone, alongside PLGO (Schloss), BVN (Magic Formula), and PAAS (CANSLIM). Burry Value and Lunch alone now share four tickers, the most concentrated two-screen overlap in the journal's history. This period the shared names cut mostly favorably: AEM's +5.96%, FSM's +4.78%, and PAAS's +5.41% all lifted both of their respective screen pairs, while only ESTC-adjacent KSPI's decline weighed on Lunch alone. LUXE, the lone pair not involving Lunch, fell −1.60% and pulled on both Piotroski and CANSLIM, though only slightly given its small weight in each.

What Period 15 Tells You

Reversals were the rule, not the exception. Magic Formula's four worst-hit Period 14 positions — ORLA, OGC, IAG, CGAU — were its four best contributors this period. CANSLIM's MU, the epicenter of Period 14's semiconductor selloff, led its Period 15 rebound. Quality Growth's DAVE went from the stock that won Period 14 almost single-handedly to the stock that did the most damage in Period 15. Three screens in a row demonstrated the same pattern: single-period extremes in this journal have tended to mean-revert hard the very next period, at least so far.

Quality Growth's concentration cuts both ways, and this time it cut deep. With only seven or eight positions, Quality Growth's results have swung on one or two names in nearly every period reviewed so far. SEZL's −11.90% alone accounted for more than the screen's entire −3.46% loss, and DAVE's reversal compounded it. The same structural feature that let DAVE single-handedly deliver a win in Period 14 let SEZL single-handedly deliver the screen's worst period on record one week later.

Piotroski becomes the new cellar-dweller on a technicality. Piotroski's −1.24% was a mild, unremarkable result — nowhere near its own worst periods. But because Magic Formula's +4.17% was so much larger than Piotroski's decline, the two screens swapped places at the bottom of the cumulative table. It is the same mechanism that pushed Magic Formula below Piotroski in Period 14, now running in reverse — a reminder that "worst screen" in the cumulative standings is a relative, not absolute, distinction.

Overlap concentration is building around Lunch and Burry Value. The two screens now share four tickers — AEM, CPRX, FSM, and HRMY — the most any two screens have shared at once in the journal. With Lunch also expanding to eighteen positions (its largest single-period growth since Period 12) and Burry Value still the largest single portfolio at thirty-four names, the two screens' fortunes are becoming more linked with each period, for better or worse.