1988
| Date | Gold | Silver | Platinum |
| 1/4/88 | 478.10 | 6.470 | 496.30 |
| 1/5/88 | 480.90 | 6.850 | 504.60 |
| 1/6/88 | 483.30 | 7.060 | 505.90 |
| 1/7/88 | 481.30 | 7.030 | 506.00 |
| 1/8/88 | 483.70 | 7.000 | 506.50 |
| 1/11/88 | 481.90 | 6.870 | 500.60 |
| 1/12/88 | 480.70 | 6.740 | 500.90 |
| 1/13/88 | 480.20 | 6.780 | 500.00 |
| 1/14/88 | 487.00 | 6.900 | 508.50 |
| 1/15/88 | 473.60 | 6.600 | 482.70 |
| 1/18/88 | 476.00 | 6.670 | 489.00 |
| 1/19/88 | 477.50 | 6.690 | 490.50 |
| 1/20/88 | 476.50 | 6.630 | 490.00 |
| 1/21/88 | 478.50 | 6.700 | 492.70 |
| 1/22/88 | 477.30 | 6.780 | 493.50 |
| 1/25/88 | 469.00 | 6.600 | 476.50 |
| 1/26/88 | 467.00 | 6.650 | 481.50 |
| 1/27/88 | 467.20 | 6.650 | 476.50 |
| 1/28/88 | 466.20 | 6.630 | 471.70 |
| 1/29/88 | 454.00 | 6.500 | 454.90 |
| 2/1/88 | 454.00 | 6.570 | 457.00 |
| 2/3/88 | 438.70 | 6.320 | 440.00 |
| 2/4/88 | 444.40 | 6.400 | 449.40 |
| 2/5/88 | 440.20 | 6.300 | 449.20 |
| 2/8/88 | 440.40 | 6.300 | 442.00 |
| 2/9/88 | 441.60 | 6.270 | 454.60 |
| 2/10/88 | 440.60 | 6.280 | 456.10 |
| 2/11/88 | 440.20 | 6.300 | 458.50 |
| 2/12/88 | 445.30 | 6.370 | 466.00 |
| 2/16/88 | 444.20 | 6.360 | 467.60 |
| 2/17/88 | 445.60 | 6.400 | 464.00 |
| 2/18/88 | 442.70 | 6.340 | 460.40 |
| 2/19/88 | 445.10 | 6.390 | 464.30 |
| 2/22/88 | 444.90 | 6.400 | 462.60 |
| 2/23/88 | 441.80 | 6.290 | 448.80 |
| 2/24/88 | 432.00 | 6.200 | 440.00 |
| 2/25/88 | 433.20 | 6.250 | 451.30 |
| 2/26/88 | 429.60 | 6.160 | 449.70 |
| 2/29/88 | 430.50 | 6.240 | 475.00 |
| 3/1/88 | 431.00 | 6.220 | 474.70 |
| 3/2/88 | 430.80 | 6.230 | 430.80 |
| 3/3/88 | 427.70 | 6.270 | 467.00 |
| 3/4/88 | 437.40 | 6.430 | 478.00 |
| 3/7/88 | 437.30 | 6.400 | 479.40 |
| 3/8/88 | 435.30 | 6.310 | 481.80 |
| 3/9/88 | 436.20 | 6.300 | 480.30 |
| 3/10/88 | 443.20 | 6.270 | 498.10 |
| 3/11/88 | 441.80 | 6.200 | 498.10 |
| 3/14/88 | 441.80 | 6.240 | 491.30 |
| 3/15/88 | 446.30 | 6.370 | 500.90 |
| 3/16/88 | 445.30 | 6.330 | 498.80 |
| 3/17/88 | 444.00 | 6.310 | 494.00 |
| 3/18/88 | 444.30 | 6.370 | 496.50 |
| 3/21/88 | 450.60 | 6.460 | 503.60 |
| 3/22/88 | 448.70 | 6.470 | 511.40 |
| 3/23/88 | 451.10 | 6.610 | 513.00 |
| 3/24/88 | 453.40 | 6.740 | 512.20 |
| 3/25/88 | 452.50 | 6.670 | 503.00 |
| 3/28/88 | 455.80 | 6.670 | 510.00 |
| 3/29/88 | 455.40 | 6.710 | 518.70 |
| 3/30/88 | 457.80 | 6.760 | 532.50 |
| 3/31/88 | 454.00 | 6.750 | 531.00 |
| 4/4/88 | 456.70 | 6.790 | 543.50 |
| 4/5/88 | 453.40 | 6.650 | 535.70 |
| 4/6/88 | 449.00 | 6.430 | 519.00 |
| 4/7/88 | 450.00 | 6.400 | 528.60 |
| 4/8/88 | 451.60 | 6.410 | 534.00 |
| 4/11/88 | 452.80 | 6.450 | 535.90 |
| 4/12/88 | 450.90 | 6.400 | 533.60 |
| 4/13/88 | 447.00 | 6.310 | 514.00 |
| 4/14/88 | 454.00 | 6.450 | 537.90 |
| 4/15/88 | 456.00 | 6.450 | 540.90 |
| 4/18/88 | 459.40 | 6.420 | 538.50 |
| 4/19/88 | 458.40 | 6.450 | 531.70 |
| 4/20/88 | 457.00 | 6.440 | 529.60 |
| 4/21/88 | 455.40 | 6.450 | 523.70 |
| 4/22/88 | 450.90 | 6.400 | 518.80 |
| 4/25/88 | 449.00 | 6.360 | 515.90 |
| 4/26/88 | 449.80 | 6.380 | 516.10 |
| 4/27/88 | 452.30 | 6.500 | 517.00 |
| 4/28/88 | 450.60 | 6.470 | 519.00 |
| 4/29/88 | 451.00 | 6.500 | 520.10 |
| 5/2/88 | 447.00 | 6.350 | 514.10 |
| 5/3/88 | 443.50 | 6.300 | 518.60 |
| 5/4/88 | 444.80 | 6.330 | 513.00 |
| 5/5/88 | 445.40 | 6.370 | 517.70 |
| 5/6/88 | 443.70 | 6.380 | 523.10 |
| 5/9/88 | 447.30 | 6.470 | 536.00 |
| 5/10/88 | 450.10 | 6.570 | 541.70 |
| 5/11/88 | 449.70 | 6.550 | 532.00 |
| 5/12/88 | 451.90 | 6.570 | 540.00 |
| 5/13/88 | 452.20 | 6.630 | 547.30 |
| 5/16/88 | 454.90 | 6.580 | 552.80 |
| 5/17/88 | 455.50 | 6.540 | 553.40 |
| 5/18/88 | 455.00 | 6.690 | 555.00 |
| 5/19/88 | 457.40 | 6.610 | 553.50 |
| 5/20/88 | 456.20 | 6.680 | 563.60 |
| 5/23/88 | 462.20 | 6.740 | 581.90 |
| 5/24/88 | 460.60 | 6.750 | 586.30 |
| 5/25/88 | 454.40 | 6.600 | 570.00 |
| 5/26/88 | 454.10 | 6.610 | 579.40 |
| 5/27/88 | 450.00 | 6.530 | 582.00 |
| 5/31/88 | 455.00 | 6.600 | 615.70 |
| 6/1/88 | 457.40 | 6.820 | 613.00 |
| 6/2/88 | 467.00 | 7.260 | 623.00 |
| 6/3/88 | 464.40 | 7.230 | 608.10 |
| 6/6/88 | 462.90 | 7.270 | 612.00 |
| 6/7/88 | 460.00 | 7.240 | 596.50 |
| 6/8/88 | 454.10 | 7.090 | 568.00 |
| 6/9/88 | 457.10 | 7.150 | 579.20 |
| 6/10/88 | 449.10 | 7.010 | 571.40 |
| 6/13/88 | 449.60 | 7.030 | 575.20 |
| 6/14/88 | 450.60 | 7.040 | 565.20 |
| 6/15/88 | 451.90 | 7.120 | 575.50 |
| 6/16/88 | 450.00 | 7.120 | 578.30 |
| 6/17/88 | 445.50 | 7.240 | 587.70 |
| 6/20/88 | 450.00 | 7.180 | 584.10 |
| 6/21/88 | 451.80 | 7.180 | 581.20 |
| 6/22/88 | 449.50 | 7.000 | 566.50 |
| 6/23/88 | 447.70 | 6.960 | 563.70 |
| 6/24/88 | 443.00 | 6.860 | 554.00 |
| 6/27/88 | 443.00 | 6.940 | 554.00 |
| 6/28/88 | 437.50 | 6.760 | 561.50 |
| 6/29/88 | 435.20 | 6.620 | 550.00 |
| 6/30/88 | 435.30 | 6.680 | 557.30 |
| 7/1/88 | 437.20 | 6.800 | 561.90 |
| 7/5/88 | 438.10 | 6.770 | 556.00 |
| 7/6/88 | 438.20 | 6.810 | 568.90 |
| 7/7/88 | 439.10 | 6.940 | 576.00 |
| 7/8/88 | 439.10 | 7.000 | 569.30 |
| 7/11/88 | 434.60 | 6.940 | 543.60 |
| 7/12/88 | 437.00 | 6.980 | 545.00 |
| 7/13/88 | 440.00 | 7.160 | 546.00 |
| 7/14/88 | 438.70 | 7.280 | 551.50 |
| 7/18/88 | 437.80 | 7.150 | 545.30 |
| 7/19/88 | 446.50 | 7.730 | 564.50 |
| 7/20/88 | 444.70 | 7.820 | 549.00 |
| 7/21/88 | 441.40 | 7.730 | 551.00 |
| 7/22/88 | 442.20 | 7.610 | 556.60 |
| 7/25/88 | 425.90 | 7.040 | 536.90 |
| 7/26/88 | 431.10 | 6.880 | 526.10 |
| 7/27/88 | 433.00 | 6.870 | 525.00 |
| 7/28/88 | 432.00 | 6.750 | 513.00 |
| 7/29/88 | 436.10 | 6.800 | 523.80 |
| 8/1/88 | 434.40 | 6.870 | 528.10 |
| 8/2/88 | 431.50 | 6.790 | 524.80 |
| 8/3/88 | 433.30 | 6.840 | 525.80 |
| 8/4/88 | 433.40 | 6.860 | 530.50 |
| 8/5/88 | 432.30 | 6.850 | 534.70 |
| 8/8/88 | 430.30 | 6.680 | 515.40 |
| 8/9/88 | 427.40 | 6.600 | 522.30 |
| 8/10/88 | 429.20 | 6.680 | 529.20 |
| 8/11/88 | 429.30 | 6.700 | 524.60 |
| 8/12/88 | 431.30 | 6.710 | 528.50 |
| 8/15/88 | 433.00 | 6.780 | 533.80 |
| 8/16/88 | 428.90 | 6.610 | 531.10 |
| 8/17/88 | 431.00 | 6.650 | 528.00 |
| 8/18/88 | 432.30 | 6.680 | 531.60 |
| 8/19/88 | 431.70 | 6.660 | 532.40 |
| 8/22/88 | 433.60 | 6.730 | 543.90 |
| 8/23/88 | 432.20 | 6.730 | 539.70 |
| 8/24/88 | 434.90 | 6.780 | 548.00 |
| 8/25/88 | 432.80 | 6.710 | 545.60 |
| 8/26/88 | 432.10 | 6.660 | 540.10 |
| 8/29/88 | 429.40 | 6.520 | 532.60 |
| 8/30/88 | 428.80 | 6.490 | 525.80 |
| 8/31/88 | 431.30 | 6.560 | 533.90 |
| 9/1/88 | 430.20 | 6.580 | 529.40 |
| 9/2/88 | 429.30 | 6.520 | 521.50 |
| 9/6/88 | 426.70 | 6.490 | 524.10 |
| 9/7/88 | 428.10 | 6.550 | 523.50 |
| 9/8/88 | 428.80 | 6.610 | 537.00 |
| 9/9/88 | 421.20 | 6.440 | 525.80 |
| 9/12/88 | 420.80 | 6.440 | 518.90 |
| 9/13/88 | 421.50 | 6.480 | 518.70 |
| 9/14/88 | 421.30 | 6.500 | 521.00 |
| 9/15/88 | 418.20 | 6.440 | 520.10 |
| 9/16/88 | 411.70 | 6.330 | 517.00 |
| 9/19/88 | 409.20 | 6.370 | 503.00 |
| 9/20/88 | 405.30 | 6.250 | 494.90 |
| 9/21/88 | 398.20 | 6.180 | 482.00 |
| 9/22/88 | 399.30 | 6.250 | 490.20 |
| 9/23/88 | 394.00 | 6.180 | 480.90 |
| 9/26/88 | 395.20 | 6.160 | 485.10 |
| 9/27/88 | 397.30 | 6.170 | 485.60 |
| 9/28/88 | 398.20 | 6.170 | 491.50 |
| 9/29/88 | 396.80 | 6.180 | 500.80 |
| 9/30/88 | 394.40 | 6.140 | 499.00 |
| 10/3/88 | 397.50 | 6.250 | 502.40 |
| 10/4/88 | 398.10 | 6.250 | 510.80 |
| 10/5/88 | 400.80 | 6.300 | 510.60 |
| 10/6/88 | 403.80 | 6.300 | 510.40 |
| 10/7/88 | 403.20 | 6.330 | 509.60 |
| 10/10/88 | 408.60 | 6.340 | 520.40 |
| 10/11/88 | 404.40 | 6.200 | 513.10 |
| 10/12/88 | 408.40 | 6.320 | 520.40 |
| 10/13/88 | 406.90 | 6.300 | 517.40 |
| 10/14/88 | 409.10 | 6.370 | 527.40 |
| 10/17/88 | 412.20 | 6.410 | 538.40 |
| 10/18/88 | 411.20 | 6.360 | 540.20 |
| 10/19/88 | 411.40 | 6.340 | 534.00 |
| 10/20/88 | 412.20 | 6.350 | 539.80 |
| 10/21/88 | 408.40 | 6.230 | 528.90 |
| 10/24/88 | 405.80 | 6.197 | 528.20 |
| 10/25/88 | 406.40 | 6.221 | 536.30 |
| 10/26/88 | 408.30 | 6.224 | 536.40 |
| 10/27/88 | 407.60 | 6.200 | 536.40 |
| 10/28/88 | 412.40 | 6.289 | 536.40 |
| 10/31/88 | 412.70 | 6.303 | 550.50 |
| 11/2/88 | 421.80 | 6.488 | 578.80 |
| 11/3/88 | 421.50 | 6.410 | 577.90 |
| 11/4/88 | 421.50 | 6.425 | 580.80 |
| 11/7/88 | 422.80 | 6.490 | 588.00 |
| 11/8/88 | 419.10 | 6.393 | 573.20 |
| 11/9/88 | 423.10 | 6.548 | 590.80 |
| 11/10/88 | 419.00 | 6.411 | 579.90 |
| 11/11/88 | 421.60 | 6.389 | 579.60 |
| 11/14/88 | 423.90 | 6.418 | 574.50 |
| 11/15/88 | 424.40 | 6.368 | 575.20 |
| 11/16/88 | 424.50 | 6.277 | 577.40 |
| 11/17/88 | 420.10 | 6.170 | 565.20 |
| 11/18/88 | 417.40 | 6.063 | 555.40 |
| 11/21/88 | 415.80 | 6.010 | 552.30 |
| 11/22/88 | 417.70 | 6.061 | 561.80 |
| 11/23/88 | 420.00 | 6.080 | 568.50 |
| 11/25/88 | 426.50 | 6.220 | 580.00 |
| 11/28/88 | 423.30 | 6.115 | 584.50 |
| 11/29/88 | 421.90 | 6.030 | 582.20 |
| 11/30/88 | 424.80 | 6.136 | 612.00 |
| 12/1/88 | 423.90 | 6.096 | 598.80 |
| 12/2/88 | 431.70 | 6.190 | 613.80 |
| 12/5/88 | 429.30 | 6.163 | 610.00 |
| 12/6/88 | 427.50 | 6.161 | 609.30 |
| 12/7/88 | 422.80 | 6.140 | 598.00 |
| 12/8/88 | 421.80 | 6.128 | 594.30 |
| 12/9/88 | 422.90 | 6.175 | 596.70 |
| 12/12/88 | 420.10 | 6.169 | 585.60 |
| 12/13/88 | 419.80 | 6.168 | 587.00 |
| 12/14/88 | 421.50 | 6.177 | 602.10 |
| 12/15/88 | 412.90 | 6.061 | 531.90 |
| 12/16/88 | 414.00 | 6.082 | 524.80 |
| 12/19/88 | 414.40 | 6.110 | 517.00 |
| 12/20/88 | 414.00 | 6.093 | 528.00 |
| 12/21/88 | 415.30 | 6.116 | 537.00 |
| 12/22/88 | 418.00 | 6.160 | 538.00 |
| 12/23/88 | 418.50 | 6.170 | 539.00 |
| 12/27/88 | 418.00 | 6.149 | 532.90 |
| 12/28/88 | 414.40 | 6.089 | 508.00 |
| 12/29/88 | 408.20 | 5.998 | 512.00 |
| 12/30/88 | 410.00 | 6.038 | 512.00 |