NORTHWEST PIPE CO

Ticker: NWPX CUSIP: 667746101 Class: Common Stock

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC's Holding History (CIK: 0001644956)

Note: Option positions (PUT/CALL) are excluded.

Q3 2018

Shares 432,771 Value ($000) $8,547 Avg Close $18.93 Range $16.65 - $21.38

Q2 2018

Shares 535,745 Value ($000) $10,377 Avg Close $20.36 Range $17.23 - $22.00

Q1 2018

Shares 670,917 Value ($000) $11,607 Avg Close $19.27 Range $16.60 - $21.36

Q4 2017

Shares 711,677 Value ($000) $13,621 Avg Close $18.52 Range $16.62 - $21.11

Q3 2017

Shares 721,626 Value ($000) $13,725 Avg Close $16.67 Range $14.50 - $19.54

Q2 2017

Shares 723,133 Value ($000) $11,758 Avg Close $14.70 Range $12.41 - $17.18

Q1 2017

Shares 599,281 Value ($000) $9,415 Avg Close $17.50 Range $15.01 - $19.55

Q4 2016

Shares 601,604 Value ($000) $10,360 Avg Close $15.40 Range $11.80 - $18.92

Q3 2016

Shares 605,089 Value ($000) $7,146 Avg Close $11.53 Range $10.35 - $12.37

Q2 2016

Shares 616,807 Value ($000) $6,649 Avg Close $9.56 Range $8.37 - $11.27

Q1 2016

Shares 631,677 Value ($000) $5,824 Avg Close $9.23 Range $7.46 - $11.33

Q4 2015

Shares 636,425 Value ($000) $7,122 Avg Close $12.62 Range $9.87 - $15.57

Q3 2015

Shares 646,914 Value ($000) $8,449 Avg Close $16.66 Range $12.48 - $20.84

Period	Shares	Value ($000)	Average Close	Price Range
Q3 2018	432,771	$8,547	$18.93	$16.65 - $21.38
Q2 2018	535,745	$10,377	$20.36	$17.23 - $22.00
Q1 2018	670,917	$11,607	$19.27	$16.60 - $21.36
Q4 2017	711,677	$13,621	$18.52	$16.62 - $21.11
Q3 2017	721,626	$13,725	$16.67	$14.50 - $19.54
Q2 2017	723,133	$11,758	$14.70	$12.41 - $17.18
Q1 2017	599,281	$9,415	$17.50	$15.01 - $19.55
Q4 2016	601,604	$10,360	$15.40	$11.80 - $18.92
Q3 2016	605,089	$7,146	$11.53	$10.35 - $12.37
Q2 2016	616,807	$6,649	$9.56	$8.37 - $11.27
Q1 2016	631,677	$5,824	$9.23	$7.46 - $11.33
Q4 2015	636,425	$7,122	$12.62	$9.87 - $15.57
Q3 2015	646,914	$8,449	$16.66	$12.48 - $20.84