It is just USEquityPricing.volume. I have this set to volume 1 000 000 for more examples, otherwise along with my price filter used, there were only two.
price = USEquityPricing.close .latest
volume = USEquityPricing.volume.latest
This also provides some visibility into it using log_data().
2019-03-21 5:45 log_data:59 INFO starting_cash $10,000,000 portfolio $10,000,000 0 positions ...
2019-03-21 5:45 log_data:117 INFO Rows: 26 Columns: 2
2019-03-21 5:45 out:79 INFO .
min mean max
price 10.0 14.084808 19.98
volume 4383991 10534562.3 42166756
2019-03-21 5:45 out:76 INFO .
_ _ _ price _ _ _
price highs ...
price volume
HPQ 19.98 9709474
X 19.78 9366696
HST 19.13 5997423
AES 17.93 6255835
HBI 17.61 4383991
MRO 17.60 10250929
KEY 16.51 15789772
HPE 15.88 9397711
NWL 15.75 7157892
price lows ...
price volume
CTL 11.910 8565223
NYCB 11.590 7262591
CLDR 11.450 6041141
COTY 11.390 9195152
RRC 11.305 5368342
SNAP 10.950 17436449
NLY 10.275 9778333
GE 10.210 42166756
UNIT 10.000 4892077
_ _ _ volume _ _ _
volume highs ...
price volume
GE 10.210 42166756
FCX 12.825 19914612
SNAP 10.950 17436449
HBAN 12.970 16195128
KEY 16.510 15789772
GOLD 13.110 15045417
RF 14.950 10771721
MRO 17.600 10250929
NLY 10.275 9778333
2019-03-21 5:45 out:79 INFO .
volume lows ...
price volume
AES 17.930 6255835
CLDR 11.450 6041141
HST 19.130 5997423
FCAU 14.850 5794643
RRC 11.305 5368342
MIK 11.990 4978883
UNIT 10.000 4892077
NWSA 12.600 4470915
HBI 17.610 4383991