diff --git a/test/emptyTradeTimingStrategy.js b/test/emptyTradeTimingStrategy.js
index 3444ff0..585329e 100644
--- a/test/emptyTradeTimingStrategy.js
+++ b/test/emptyTradeTimingStrategy.js
@@ -5,7 +5,7 @@ require('should');
 const {TradeTimingStrategy} = require('../index.js');
 
 let tradeAdvisor = null;
-before(function(){
+beforeEach(function(){
   tradeAdvisor = new TradeTimingStrategy();
 });
 it('is a (constructor) function', function(){
@@ -27,12 +27,14 @@ it('newPeriod() returns self', function(){
   tradeAdvisor.newPeriod().should.equal(tradeAdvisor);
 });
 it('newTrade() throws RangeError()', function(){
+  tradeAdvisor.newPeriod();
   function bad(){
     tradeAdvisor.newTrade();
   }
   bad.should.throw(RangeError);
 });
 it('newTrade(-3) throws RangeError()', function(){
+  tradeAdvisor.newPeriod();
   function bad(){
     tradeAdvisor.newTrade(-3);
   }
@@ -42,30 +44,54 @@ it('has a method suggestedBid', function(){
   tradeAdvisor.suggestedBid.should.be.a.Function();
 });
 it('.suggestedBid() throws RangeError', function(){
+  tradeAdvisor.newPeriod();
   function bad(){
     tradeAdvisor.suggestedBid();
   }
   bad.should.throw(RangeError);
 });
 it('.suggestedBid(100) returns undefined', function(){
+  tradeAdvisor.newPeriod();
   assert.ok(tradeAdvisor.suggestedBid(100)===undefined);
 });
+it('.suggestedBid(100,{currentBid:10}) returns undefined', function(){
+  tradeAdvisor.newPeriod();
+  assert.ok(tradeAdvisor.suggestedBid(100,{currentBid:10})===undefined);
+});
+it('.suggestedBid(100,{currentAsk:200}) returns undefined', function(){
+  tradeAdvisor.newPeriod();
+  assert.ok(tradeAdvisor.suggestedBid(100,{currentAsk:200})===undefined);
+});
+it('.suggestedBid(100,{currentBid:10,smooth:0.001}) returns undefined', function(){
+  tradeAdvisor.newPeriod();
+  assert.ok(tradeAdvisor.suggestedBid(100,{currentBid:10,smooth:0.001})===undefined);
+});
+it('.suggestedBid(100,{currentAsk:200,smooth:0.001}) returns undefined', function(){
+  tradeAdvisor.newPeriod();
+  assert.ok(tradeAdvisor.suggestedBid(100,{currentAsk:200,smooth:0.001})===undefined);
+});
 it('.suggestedBid(100,{currentBid:39,currentAsk:40,smooth:0.001}) returns 40', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedBid(100,{currentBid:39,currentAsk:40,smooth:0.001}).should.equal(40);
 });
 it('.suggestedBid(100,{currentBid:38,currentAsk:40,smooth:0.001}) returns 40', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedBid(100,{currentBid:38,currentAsk:40,smooth:0.001}).should.equal(40);
 });
 it('.suggestedBid(100,{currentBid:1,currentAsk:40,smooth:0.001}) returns 40', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedBid(100,{currentBid:1,currentAsk:40,smooth:0.001}).should.equal(40);
 });
 it('.suggestedBid(100,{currentBid:10,currentAsk:70,smooth:0.001}) returns 55', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedBid(100,{currentBid:10,currentAsk:70,smooth:0.001}).should.equal(55);
 });
 it('.suggestedBid(100,{currentBid:10,currentAsk:500,smooth:0.001}) returns 55', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedBid(100,{currentBid:10,currentAsk:500,smooth:0.001}).should.equal(55);
 });
 it('has a method suggestedAsk',function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedAsk.should.be.a.Function();
 });
 it('.suggestedAsk() throws RangeError', function(){
@@ -75,14 +101,18 @@ it('.suggestedAsk() throws RangeError', function(){
   bad.should.throw(RangeError);
 });
 it('.suggestedAsk(100) returns undefined', function(){
+  tradeAdvisor.newPeriod();
   assert.ok(tradeAdvisor.suggestedAsk(100)===undefined);
 });
 it('.suggestedAsk(50,{currentBid:100,currentAsk:200,smooth:0.001}) returns 125', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedAsk(50,{currentBid:100,currentAsk:200,smooth:0.001}).should.equal(125);
 });
 it('.suggestedAsk(80,{currentBid:100,currentAsk:119,smooth:0.001}) returns 100', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.suggestedAsk(80,{currentBid:100,currentAsk:119,smooth:0.001}).should.equal(100);
 });
 it('.pricesWithProbabilities(1) returns []', function(){
+  tradeAdvisor.newPeriod();
   tradeAdvisor.pricesWithProbabilities(1).should.deepEqual([]);
 });
diff --git a/test/singlePeriodTradeTimingStrategy.js b/test/singlePeriodTradeTimingStrategy.js
index 9a53176..f8d5461 100644
--- a/test/singlePeriodTradeTimingStrategy.js
+++ b/test/singlePeriodTradeTimingStrategy.js
@@ -17,6 +17,12 @@ describe('[single period, 4 trades: p=130,110,125,140]', function(){
       .newTrade(140)
       .newPeriod();
   });
+  it('.pricesWithProbabilities(1,{sort:byPriceAscending, below:100, smooth:0.001}) should be []',function(){
+    tradeAdvisor.pricesWithProbabilities(1,{sort:byPriceAscending, below:100, smooth:0.001}).should.deepEqual([]);
+  });
+  it('.pricesWithProbabilities(1,{sort:byPriceAscending, above:200, smooth:0.001}) should be []',function(){
+    tradeAdvisor.pricesWithProbabilities(1,{sort:byPriceAscending, below:100, smooth:0.001}).should.deepEqual([]);
+  });
   it('.pricesWithProbabilities(1,{sort: byPriceAscending}) should be [[130,1]]', function(){
     tradeAdvisor.pricesWithProbabilities(1,{sort:byPriceAscending}).should.deepEqual([[130,1]]);
   });